We are to choose the best option which correctly uses the verb "harrow".
The sentence which correctly uses the verb "harrow" is The dog harrowed the poor cat until it finally hissed and fled the room.
From the dictionary entry: harrow is a farm implement / to inflict great stress
According to the dictionary entry, the sentence which used the verb harrow completely is: The dog harrowed the poor cat until it finally hissed and fled the room.
The dog has inflicted great stress on the cat by harrowing it which made the cat leave the room.