Take a look at the sentence again:
To protect her delicate hands, Fran will not rake the yard, do the dishes,
or __________.
The blank requires a future tense verb. You chose won't scrub the bathtub, which contains too many words, causing a parallelism error. Since the second item in the series, do, drops the will not [the words are understood to be there], the third item must do the same.
Before you continue, review the rules for parallel structure.
Go back to the sentence to try again.