Answer the following question given this paragraph: 

Primates tend to have bigger brains for their body size than other mammals. This is reflected in their relatively high level of intelligence and their ability to learn new behaviors.


Q: Reflected in their relatively high level of intelligence and their ability to learn new behaviors, what organs tend to be relatively large in primates?

 Choices:

- lungs

- hearts

- kidneys

- brains

A:
brains
