​When humans or rats have a variety of tasty foods available,

A) ​humans increase their food intake, but rats do not.
B) ​rats increase their food intake, but humans do not.
C) ​both rats and humans increase their food intake.
D) ​food intake remains constant for both.

Both rats and humans increase their food intake when a variety of tasty foods are available. This is known as the "variety effect" and is thought to be due to sensory-specific satiety, where the pleasurable sensation of a certain food decreases with repeated consumption, leading us to seek out different flavors and textures. Therefore, when presented with a variety of options, we are more likely to continue eating and try out different foods.