The correct option is D all the above
Ethylene induces flowering in pineapple. Ethylene is also used to make all the plants (pineapple) flower at the same time. Making the plants bloom at the same time makes sure that the fruits are also produced simultaneously. This process is called synchronising the fruit-set. (Fruit set is the process by which flowers become fruits). The advantage of this is that all the fruits can be harvested at the same time.