Array
(
    [1872] => Array
        (
            [parent_category_id] => 1872
            [parent_category] => Array
                (
                    [id] => 1872
                    [slug] => health-medical
                    [name] => Health and Medical
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Nutrition
                            [slug] => nutrition
                            [id] => 1873
                        )

                )

        )

    [1772] => Array
        (
            [parent_category_id] => 1772
            [parent_category] => Array
                (
                    [id] => 1772
                    [slug] => history-social-studies
                    [name] => History and Social Studies
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => American History
                            [slug] => american-history
                            [id] => 1773
                        )

                    [1] => Array
                        (
                            [name] => Anthropology
                            [slug] => anthropology
                            [id] => 1782
                        )

                    [2] => Array
                        (
                            [name] => Archaeology
                            [slug] => archaeology
                            [id] => 1784
                        )

                    [3] => Array
                        (
                            [name] => European History
                            [slug] => european-history
                            [id] => 1774
                        )

                    [4] => Array
                        (
                            [name] => Geography
                            [slug] => geography
                            [id] => 1776
                        )

                    [5] => Array
                        (
                            [name] => Social Studies
                            [slug] => social-studies
                            [id] => 1779
                        )

                    [6] => Array
                        (
                            [name] => World History
                            [slug] => world-history
                            [id] => 1775
                        )

                )

        )

    [1744] => Array
        (
            [parent_category_id] => 1744
            [parent_category] => Array
                (
                    [id] => 1744
                    [slug] => science
                    [name] => Science
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Anatomy
                            [slug] => anatomy
                            [id] => 1749
                        )

                    [1] => Array
                        (
                            [name] => Biology
                            [slug] => biology
                            [id] => 1746
                        )

                    [2] => Array
                        (
                            [name] => Genetics
                            [slug] => genetics
                            [id] => 1753
                        )

                    [3] => Array
                        (
                            [name] => Physical Science
                            [slug] => physical-science
                            [id] => 1745
                        )

                    [4] => Array
                        (
                            [name] => Physiology
                            [slug] => physiology
                            [id] => 1750
                        )

                )

        )

)