Mammalian Eyes Sense Light Because the Photoreceptor Cells Have Molecules

Mammalian eyes sense light because the photoreceptor cells have molecules called opsins, which change structure when exposed to light. Which of the following plant molecules would be analogous to mammalian opsins in their light-sensing ability?

A) auxin and phytochrome
B) auxin and Pfr
C) Pfr and phytochrome
D) cytokinins and phototropins
E) abscisic acid (ABA) and Pfr