I would go with d or a as my best guess
I would say its an imperative verb, because its giving a command.
<span>B. We were walking by the lake when we heard a siren.
C. By the time I graduated, I had attended three different high schools.
D. Though he had been rude at first, Rupert eventually won over the congregation
These three sentences are all correct, because even if the verb tense shifts it still makes sense within the context of the situation.</span>
