Which substance is commonly used to remove the green color from citrus fruits during the degreening process?

Explanation

The degreening of citrus fruits is typically carried out by applying Ethrel, a plant growth regulator that releases ethylene to accelerate the removal of the green pigment. While ethylene itself is involved in the process, Ethrel is the commercial formulation used. Ethephon (often confused with Ethrel) is a different compound, and cytokinins do not play a role in degreening.