My best guess would be A, because switchback means to like turn you around. hope it helps ^_^
to better explain some of the ideas in the main text is your answer.
The typical number of elective credit hours that is needed to earn a bachelor's degree is in letter A. 18. Base on many school that i know. When it is below 18 it wouldn't be accredited by the school. I hope you are satisfied with my answer and feel free to ask for more
