I think it’s the second answer
A they are talking about the main thing frank is doing
The Battle of Antietam was a crucial victory for the Union Army, because was the first major battle in the American Civil War to take place on their soil. It was also the bloodiest battle of the war and was a victory for the Union Army, because the Confederate Army retreated first and gave President Abraham Lincoln the confidence to do the Emancipation Proclamation, subtracting the power of France and the United Kingdom to be in support of the Confederate side.
The answer is A. sewing.
A gerund is a verb that has -ing at the end of it, so sewing is the correct answer! Although gerunds use verbs, they can also work as nouns, like it does here.
