Ethylene is used for

1. retarding ripening of tomatoes

2. the hastening of ripening of fruits

3. slowing down the ripening of apples

4. Both 2. and 3.


(b) Ethylene is a gaseous hormone and is produced by the ripened fruits and also help in ripening of other unripened fruits, Other mentioned functions are not of ethylene.
Page 250, XI NCERT