The correct answer is C. Allow.
To permit something is to give permission for it to happen. For example, you might permit someone to enter your house or to use your car.
To forbid something is to order or command that it should not happen. For example, you might forbid your children to watch TV after 9pm.
To give something is to transfer ownership of it to someone else. For example, you might give your friend a gift for their birthday.
To preserve something is to protect it from harm or destruction. For example, you might preserve a piece of art by putting it in a museum.
In the context of the question, the correct answer is C. Allow. This is because the question is asking for the word that means “to give permission for something to happen.” The other options do not mean this. Option A, Give, means to transfer ownership of something to someone else. Option B, Forbid, means to order or command that something should not happen. Option D, Preserve, means to protect something from harm or destruction.