Final answer:
The insect in the Order Hemiptera that secretes honeydew is the d)mealy bug.
Step-by-step explanation:
The insect that is in the Order Hemiptera and secretes honeydew is the mealy bug.
Honeydew is a sugary fluid that is excreted by some insects, including mealybugs. Other insects, like leafhoppers, also secrete honeydew. Honeydew is an important food source for ants, which often collect and feed on it.
So, the correct answer is option d) mealy bugs.