What helps in flowering?
a)	Cytochrome	b)	ABA	c)	Phytochrome	d)	Ethylene

(c)

Phytochrome is an amorphous photoreceptor protein pigment. It exists in two states, i.e., phytochrome Red  and phytochrome far-red

It is considered that during the day,  from of the phytochrome is accumulated in the plant which is inhibitory to flowering in short-day plants, but is stimulatory in long day plants.