B) El maíz.
=
Corn.
Why?
A) El ganso is a goose; we all know a goose is a bird and a bird is a/n animal.
C) La gallina is a chicken, which is also a bird, and as I said previously, a bird is a/n animal.
D) El lobo is a wolf, which is a mammal; which is an animal.
This is how we get B) El maíz.
Hope this helps!~