The sentence which is written in a second-person point of view is the one that follows:
C. Whatever you decide, it'll be clever.
The subject is "you". Therefore, the sentence is written in a second-person point of view. The other alternatives are written in different points of view:
A- We shouldn't... (first-person plural)
B- I have...(first-person singular)
D- He crossed (third-person singular)