1. Both - you can see it on the screenshot (Deleting product options.png).
Check it yourself, just remove all product filters and see what is exported after that
https://core.extraparts.com.ua/app/product/681216/edit/.2. product_option_value is the Option Values. In the action settings and the task, we were talking about Options, not Option Values.
Why then should a product in opencart leave empty options (product_option) without values if they were removed in BOX?