GENERAL HISTOLOGY

Detailed explanation-1: -Complete answer: b) Glucagon-insulin hormone is an antagonist to glucagon because it reacts opposite to the function of insulin. Insulin role is to maintain the glucose level in the blood stream whereas glucagon hormone is known for raising the concentration of glucose in blood.

Detailed explanation-2: -Insulin and glucagon, calcitonin and parathyroid hormone are antagonistic hormones because their actions are completely opposite. Glucagon increases blood glucose level and insulin decrease blood glucose level. Parathyroid hormone increases blood calcium level and calcitonin decrease the blood calcium level.

Detailed explanation-3: -Calcitonin is involved in helping to regulate levels of calcium and phosphate in the blood, opposing the action of parathyroid hormone. This means that it acts to reduce calcium levels in the blood.