Biology

Answer: B

Explanation:

Correct option: Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormones.
Thyroid hormones are essential for regulating the body's metabolism.
When there is a deficiency, the body's metabolic rate slows down.
This leads to symptoms such as weight gain because the body burns fewer calories, fatigue due to the reduced energy production, and a low heart rate as the body's overall activity level decreases.

Incorrect options:

Hyperthyroidism (A) is the opposite of hypothyroidism. In hyperthyroidism, the thyroid gland overproduces thyroid hormones.
This results in an increased metabolic rate, leading to weight...