Get data from Theme Options and use them into meta options field in custom post type

You can use the get_option function on the back-end too. There are several possibilities on how to pass your option value to your script:

  1. Use wp_localize_script function to pass PHP values to your script (see WordPress Codex page for this function).
  2. Print your option value along with name and name2 values inside a script tag.
  3. Use AJAX. When user clicks your checkbox A, you send an AJAX request to the server requesting the value of your option.

The rest is just a matter of joining all the pieces together and putting them inside your textfield using jQuery.