Could someone explain why this is wrong? which of the following concerning allosteric

Could someone explain why this is wrong? which of the following concerning allosteric inhibitors is not true? a) can inhibit an enzyme by changing the shape of the active site b) can inhibit an enzyme by changing the shape of the enzyme c) can inhibit an enzyme by covering the active site d) all of these are not true the answer was d, but i don't understand why. i put b because it only changes the shape of the active site and not the enzyme itself, but that was wrong.