Driving is difficult if the weather is stormy. The weather is stormy.

A. Driving is not difficult

B. Not possible

C. Driving is difficult

D. If driving is difficult, then the weather is stormy

I am at the age of driving it i would say it hard to drive when the weather is stormy. so i would say C

D: = Driving is difficult

W: = The weather is stormy

The sentence means:

W = = > D

Read as "W implies D"

Which basically just means:

Whenever we have W, we have D, too! Always. We can't have W without also having D.

In this case, we are given W (the weather is stormy). So, we must also have D! (Driving is difficult)

The answer is C.