Final answer:
The nurse would monitor for a hypoglycemic episode before lunch.
Step-by-step explanation:
The nurse would monitor for a hypoglycemic episode before lunch. Insulin injections, such as the Humulin N insulin received by the adolescent with diabetes, allow for transport and storage of glucose, which leads to a decrease in blood glucose levels. Therefore, after receiving the insulin in the morning, the blood glucose levels will decrease by lunchtime. The nurse should monitor for hypoglycemia to ensure that the blood glucose levels do not drop too low.