Final answer:
Injecting insulin into the body lowers blood glucose levels, which in normal individuals is balanced by glucagon secretion. In diabetic patients, the response may differ due to defective receptors, antagonists, or antibodies. The correct option is 2.
Step-by-step explanation:
Injection of insulin into the body results in a fall in the blood glucose level due to the utilization of glucose by cells with the aid of insulin. In normal or insulin-responsive individuals, this decrease in glucose is subsequently balanced out by the secretion of the hormone glucagon, which acts to increase blood glucose levels when they are low.
However, for patients with diabetes mellitus, particularly those with insulin-independent diabetes mellitus (IIDM) or insulin-dependent diabetes mellitus (IDDM), the response can be altered due to factors like defective insulin receptors, the presence of insulin antagonists, or antibodies to insulin.