Student or Learner
I've recently come across the following grammar task with three possible answers and I'm not sure which one I should choose:
When he arrived she ....................... for two hours to talk to him.
a) had been waiting;
b) was waiting;
c) has been waiting.
I think that the right anwer is a) because it happened in the past and it's followed by the word for so it excludes answer b). Am I right? Thank you in advance.
a) is correct.