Which sentence uses punctuation correctly? (Look carefully!)

a) To try to keep busy, Rapunzel read books, painted, played games, and cleaned.

b) To try to keep busy; Rapunzel read books; painted; played games; and cleaned.

c) To try to keep busy: Rapunzel read books, painted, played games, and cleaned.

d) To try to keep busy Rapunzel read books: painted: played games: and cleaned.