Imagine That You and Charles Darwin Are Standing in a Barn

Imagine that you and Charles Darwin are standing in a barn, looking at a newborn litter of kittens. There are differences in the kittens in terms of size, colouring, temperament and appetite. As you observe the kittens, you ask Mr. Darwin which of the kittens will be most "fit" in terms of natural selection. What would Mr. Darwin be most likely to say in response to your question?

A) "We won't know which one is most fit until we can determine how many offspring each of them will have."
B) "Well, because they are all related and carry the same genes, they all have equal fitness."
C) "That grey one, because he is the strongest and the most aggressive."
D) "The calico, because she is most attractive."