4) The forest fire / to destroy / the farm / since 3 p.m.

Question: 4) The forest fire / to destroy / the farm / since 3 p.m.

Analysis: The subject is 'The forest fire' (singular). 'Since 3 p.m.' indicates a starting point in time for an ongoing action. The present perfect continuous tense is suitable.

Possible Answer: The forest fire has been destroying the farm since 3 p.m.