To answer the question, consider the following: He is the pet greyhound of the Simpson family.is the reasoning for what question and answer pair?
Q: Santa's Little Helper is a recurring character in the American animated television series The Simpsons. He is the pet greyhound of the Simpson family. The dog was introduced in the first episode of the show, the 1989 Christmas special "Simpsons Roasting on an Open Fire", in which his owner abandons him for finishing last in a greyhound race. Homer Simpson and his son Bart, who are at the race track in hope of winning some money for Christmas presents, see this and decide to adopt the dog.

Based on this passage, what kind of dog is santa's little helper on the simpsons?
A: greyhound