Question

which of the following is a side effect of biguanides?
hyperglycemia
hypoglycemia
rapid heart rate.
weight loss

Explanation:

Biguanides (e.g., metformin) are used for diabetes. They don't typically cause hypoglycemia (unlike some other diabetes meds) or hyperglycemia (they lower blood sugar). Rapid heart rate isn't a main side effect. Weight loss can occur as a side effect of biguanides, especially metformin, due to effects on glucose metabolism and appetite.

Answer:

Weight loss