Why rhodophyta exhibit a red colour ?

A. Since most rhodophyta grow at great depths, the chlorophyll can only absorb light in the red area of the spectrum.

B. The wavelengths of light that are absorbed by chlorophyll are passed to phycoerythrin (a red pigment).

C. Red pigment of rhodophyta absorbs all the light waves.

D. The light reaching the greatest depth in water is in the blue-green region of the spectrum, is absorbed by phycoerythrin.