Which sentence is wrong because it's not parallel?
a grandad's tomato was not only the biggest one at the fair but also the winner of the blue ribbon.
b not only was grandad's tomato bigger than all others at the fair but also the winner of the blue ribbon.
c not only was grandad's tomato bigger than all others at the fair, but it also won the blue ribbon.
d not only was grandad's tomato the biggest one at the fair, but it was also the winner of the blue ribbon.