<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def all_selected_options(self):
 """Returns a list of all selected options belonging to this select tag"""

        ret = []
        for opt in self.options:
            if opt.is_selected():
                ret.append(opt)
        return ret