"Why don't you take extra classes in English if you want to become a

A. My friend advised me to take extra classes in English only if I wanted to become a tourist guide. 

B. In my friend's opinion, I will never become a tourist guide if I don't take extra classes in English. 

C. In my friend's opinion, taking extra classes in English is necessary if I wanted to become a tourist guide. 

D. My friend suggested I take extra classes in English if I wanted to become a tourist guide.