**Core Concept**
The basal metabolic rate (BMR) is the amount of energy expended by the body at rest, representing the rate at which the body uses energy to maintain basic bodily functions. Various factors can influence BMR, including age, sex, weight, and body composition.

**Why the Correct Answer is Right**
The correct answer is related to the concept of hyperthyroidism, a condition characterized by an overproduction of thyroid hormones. Thyroid hormones play a crucial role in regulating metabolism, and an excess of these hormones can lead to an increase in BMR. This is because thyroid hormones stimulate the breakdown of fats, carbohydrates, and proteins in the body, resulting in an increased energy expenditure.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not directly related to an increase in BMR. While certain medications may have a negligible effect on BMR, it is not a primary mechanism of action.
**Option B:** This option is incorrect because a decrease in body temperature would actually lead to a decrease in BMR, not an increase.
**Option C:** This option is not directly related to an increase in BMR. While certain medical conditions may have a secondary effect on BMR, it is not a primary mechanism of action.

**Clinical Pearl / High-Yield Fact**
Thyroid hormones are essential for regulating metabolism, and an excess of these hormones can lead to an increased BMR, resulting in weight loss, tremors, and other symptoms associated with hyperthyroidism.

**Correct Answer: C. Hyperthyroidism increases BMR by stimulating the breakdown of fats, carbohydrates, and proteins in the body, resulting in an increased energy expenditure.**