The question does not have the option which are:
depleted in red light; inactive form
enriched in red light; active form
depleted in red light; active form
enriched in red light; inactive form
depleted in red light; inactive form
Answer:
depleted in red light; inactive form
Explanation:
The understory is the lower portion of the forest canopy which is characterised by the shade-tolerant species of the plants.
The light that reaches the lower portion or in the understory is depleted in the red light wavelength.
The phytochromes are the photoreceptor or blue-green pigment which response to the red and far-red wavelength. The low light converts the phytochrome to its inactive form Pr form which is reversible.
Thus, the selected option is correct.
