On caribbean islands with mountains the windward slopes facing the trade winds force air upward causing rainfall as a result areas immediately to the leeward of the mountains have a microclimate with sparse precipitation called an?
a. slope shadow
b. drought shadow
c. enso
d. rain shadow

The correct answer is letter D. Rain shadow refers to this specific phenomenon. This happens because the mountains tend to block the precipitation causing the area below it to experience a dry climate. This is why most seasons in the Caribbean Islands are usually tropical and the weather is mostly sunny. 

I'm pretty sure it's c. extremely gradual but not 100% sure though.