2 calls to options_array_transpose()

_options_form_to_storage in modules/field/modules/options/options.module: Transforms submitted form values into field storage format.
_options_storage_to_form in modules/field/modules/options/options.module: Transforms stored field values into the format the widgets need.

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.