A Reindeer is also known as caribou, but in the taxonomic sense both reindeer/caribou and other types of deer are in the same family (cervidae). (within a family are subfamilies and within those are genuses/genera). However, reindeer/caribou are in a genus together. There are many different genera in the cervidaae family.
So the answer to the quiz is probably reindeer, but family (taxonomical) is an incorrect word to use.