I admit ..... about the boss's wrongdoings, but what was I supposed to do about them? He's the boss!

I admit ..... about the boss's wrongdoings, but what was I supposed to do about them? He's the boss! (*) know (*) knew (*) knowing (*) to know


This is a companion discussion topic for the original entry at https://english.best/questions/21411,i-admit-___-about-the-bosss-wrongdoings-but-what-was-i-supposed-to-do-about-them-hes-the-boss/