Final answer:
The glands that secrete digestive enzymes in an earthworm are found in the intestine, making 'd) Intestine' the correct answer.
Step-by-step explanation:
The glands that secrete enzymes to help digest the worm's food are located in the intestine. The alimentary canal of an earthworm, which is an example of an animal with an advanced digestive system, includes several specialized structures. Following food ingestion, the food is stored in the crop, then passes into the gizzard, where it is ground up. After the gizzard, food moves into the intestine, where digestive enzymes break it down further, nutrients are absorbed, and waste is eliminated as feces. Thus, the correct answer to the question is d) Intestine.