Answer:
Option B, Aerial roots allow the orchid to attach itself to trees.
Explanation:
The options for this question are -
Aerial roots preserve water in the orchid.
Aerial roots allow the orchid to attach itself to trees.
Aerial roots produce food for the orchid through photosynthesis.
Aerial roots anchor the orchid to the ground.
Solution
Option D is incorrect because anchoring plants to the ground is not a specialized function as all the plants are grounded with the help of their roots only. Preserving water is also not a specialized function of roots. Roots cannot perform photosynthesis because they do not have chlorophyll and also they are not exposed to sunlight since they are buried deep inside the soil.
Specialized roots of Orchids allow them to climb over other trees and remain intact there in order to obtain oxygen and water from the air.
Thus, B is correct
