A giraffe’s tongue is up to 21 inches long. However, the normal length of a giraffe’s tongue is around 18 inches only. Aside from having a long tongue, a giraffe’s tongue is also known for having grey, purple or blue coloration at its tip and pink on its back and underside. Some sources claim that a giraffe’s tongue can extend up to 20 inches only.
The only reason why we picked the answer as letter D because it is the closest among all the given choices. We cannot pick letter A because five inches is too short. We also cannot pick letters B and C because obviously a giraffe’s tongue is normally around 18 inches.