**Core Concept**
Insulin is a hormone produced by the beta cells of the pancreas that plays a crucial role in regulating blood glucose levels. After a large dose of insulin injection, the body experiences a rapid decrease in blood glucose levels due to increased glucose uptake by cells and glycogen synthesis.

**Why the Correct Answer is Right**
When a large dose of insulin is administered, it triggers a cascade of hormonal changes in the body. Glucagon, a hormone produced by the alpha cells of the pancreas, is suppressed due to the decrease in blood glucose levels. As a result, glucagon levels decrease, while insulin levels increase, leading to a state of increased insulin activity. The pancreas also releases other hormones, such as growth hormone and cortisol, which help to mobilize glucose stores from the liver and adipose tissue. However, the primary effect of insulin is to decrease blood glucose levels through increased glucose uptake by cells.

**Why Each Wrong Option is Incorrect**
**Option A:** Glucagon levels increase in response to the large dose of insulin injection. This is incorrect because glucagon levels actually decrease in response to increased insulin activity.

**Option B:** The pancreas releases epinephrine in response to the large dose of insulin injection. This is incorrect because epinephrine is released in response to hypoglycemia, but the primary effect of insulin is to decrease blood glucose levels.

**Option C:** The large dose of insulin injection has no effect on the levels of other hormones in the body. This is incorrect because the large dose of insulin injection triggers a cascade of hormonal changes in the body, including the suppression of glucagon and the release of growth hormone and cortisol.

**Clinical Pearl / High-Yield Fact**
After a large dose of insulin injection, patients may experience hypoglycemia, which can be treated with glucose supplements or glucagon injections. It is essential to monitor blood glucose levels closely after insulin administration to prevent hypoglycemia.

**Correct Answer: D. Insulin levels increase, while glucagon levels decrease in response to the large dose of insulin injection.**