Answer:
A. Carotene
Explanation:
It is an orange/red pigment which is seen during the fall.
I think the answer is A because direct sunlight causes dyes in clothes to fade quietly.
The answer is single opening. The gastrovascular cavity varies from the alimentary canal in that only the gastrovascular cavity has only a single opening. In addition, an alimentary canal has two openings and food moves over it unidirectional. The gastrovascular cavity is a construction establish in primitive animal phyla. It is accountable in cooperation with the digestion of food and the transportation of nutrients all over the body.