I still do n't know what was causing the massive failure because I saw no wrecked cars . I can only assume the cluster arose from several semi trucks all huddled together . Once we made it past that , we still had to drive to the exit and park .
According to the above context, choose the best option to answer the following question.
Question: What was causing the delay ?
Options:
A. A roadblock
B. A crash
C. A group of semi trucks
D. None of the above choices .


C