It is essential that your skin ____________ to its youthful condition.
A. restore
B. be restored
C. is restored
D. will restore
In my opinion, they all seem correct except for D.
Help.
A and D are saying that your skin will act, and presumably on something else. So if you do mean that it will restore itself, you would need to add the 'itself' explicitly. (Or specify something else.)
As for C, since it's in the present tense, it's not (AFAIK) the correct way to say it, but I think it is used that way. what I would use. However, see the comments for more information.
B seems the best.