Phytochrome is a Lipoprotein. Flavoprotein. Chromoprotein. Glycoprotein.

Proteins having pigmented prosthetic group are referred to as chromoproteins. Phytochromes is a chromoprotein, e.g., phytochrome A and phytochrome B that regulate flowering in plants by under different light conditions by absorption of red or far red light by their pigment. Therefore, the correct answer is option B.