What Is the Effect If There Is an Illegal and Impossible

What is the effect if there is an illegal and impossible condition in a simple donation?

A) The illegality or impossibility of the condition will annul not only the condition but also the obligation even if the impossible condition is a condition not to do.
B) The illegality or impossibility of the condition will annul not only the condition but also the obligation unless the impossible condition is a condition not to do.
C) The donation is valid because the illegal or impossible condition is simply considered as not impose
D) Hence, the condition is void but the donation is valid.