When researchers Blakemore and Cooper exposed newborn kittens to either vertical or horizontal stripes—and nothing else—for several months, it was found that ________

a. the kittens became completely blind.
b. the kittens ran to play only when the researcher held up a bar matching their visual experience.
c. the perception of vertical stripes is innate, and so some kittens functioned in a normal manner.
d. the perception of horizontal stripes is innate, and so some kittens functioned in a normal manner.

Answer: b