Final answer:
The fruit that will not ripen after being picked is a pineapple, which is a non-climacteric fruit. Unlike climacteric fruits such as bananas and avocados, which release ethylene to ripen even after picking, pineapples must be harvested ripe.
Step-by-step explanation:
The question asks which fruit will not ripen after being picked. This is characteristic of a non-climacteric fruit. The fruits listed as options include an orange, apple, grape, and pineapple. Among these, the correct answer is D. pineapple. Pineapples do not ripen once picked, which means they should be harvested when they are fully ripe if we want them to be sweet and ready to eat.
Fruits like bananas and avocados, on the other hand, are climacteric fruits, which can ripen after being picked. These fruits release a hormone called ethylene, which facilitates the ripening process. When placed in a brown bag, the ethylene concentration increases, speeding up the ripening. Abscisic acid, another plant hormone mentioned in the context, is actually associated with inhibiting growth, promoting leaf detachment, and inducing seed dormancy, not with ripening.