Reply to "Inversion in comparative sentence"

Thank you, David. How patient you are!

Are you bored with answering my questions? ♥

May I ask the last question in this post? 

Assume that the first part of my question below were correct, would there be two possible choices C and D? 

(I would like to ask that because it was a question in the English -2017- national -test in my country for those who wanted to get higher education, and it caused a lot of controversy because many teachers of English didn't see the given key D as the only answer. According to them, there was more than one suitable answer, and C was totally correct.)

novice posted:


The larger the area of forest is destroyed, .......

A. the most frequent natural disasters are

B. the most frequently natural disasters occur

C. the more frequent are natural disasters

D. the more frequently natural disasters occur

Which option is the best to fill in the blank?