Which of these sentences does not use standard capitalization?

Which of these sentences does not use standard capitalization?
A . Although she was invited, Alana claimed she was “way too busy” to join us for coffee.
B . Sarah asked, “Where are we going tonight after the movie?”
C . Harry applied to start college in the spring, as he planned to take a “gap semester” in the fall after his high school graduation.
D . Traveling from Alaska to Argentina on a motorcycle: this was the trip he had waited his whole life to take.

Answer: D