She <span>had been working</span> on the project for 2 days before she finished it. So B is the only right one as it's a continuous action before an action with an exact defining past perfect continuous. Also there's a key word "for" that can help us to find out the tense.
Examples from social media users.
Data from Pew Research
Quotations from a research study
It proves that they too have laws of their own and the white people are trying to diminish their freedom laws with oppression laws.<span />
Answer: Bring
Explanation:
A verb is an action word. In this sentence, bring is the only word that's close to being an action.
