This question has options. Answer the question about text:

Then I had met another guy who was going to the same university in the flight . So we went around the houston airport for a while , as our ground shuttle was supposed to pick us up at 9:30 pm . The shuttle arrived at the airport around half an hour late .

Why may the shuttle have been late ?
OPTIONS:
(A). There was very heavy traffic around the airport at the time .
(B). The driver was going to drive them to the university instead .
(C). The driver wanted them to miss their flight .
(D). None of the above choices .
(A).