Ripening of fruits can be promoted by:

Explanation

Ethylene gas is known as the 'ripening hormone' because it initiates the ripening process in fruits. It causes changes such as increased respiration rate, conversion of starches to sugars, and softening of the fruit cell walls, making the fruit sweeter and more palatable. On the other hand, gibberellic acid focuses on growth processes like stem elongation, indole acetic acid is involved in general plant growth, and 'Flsrcen' is not a valid term in plant biology.