Question

What causes a ray of white light to split into seven colors when passed through a prism? A. refraction B. reflection C. filtering D. absorption

Answer 1

Refraction causes the light to bend. Each wavelength bends by a slightly different amount.

The light doesn't "split into 7 colors". It smears, into all of the thousands of colors that eyes can detect, plus some that they can't.

Answer 2

Refraction causes the ray of white light to be split into seven different colors.

Answer: A. Refraction