新入社員の時、毎晩遅くまで___。
Q. Which form expresses 'I was made to work late every night'?
Translation
When I was a new employee, I was made to work late every night.
Explanation
働かされる is the causative-passive of 働く: the subject was forced to work. 働かせました would mean the subject made someone else work — the opposite viewpoint.