Step 1: Understanding the Concept:
Hormones regulate the secretion of other hormones.
Some hormones inhibit insulin release.
Step 2: Key Formula or Approach:
No specific formula.
Need to know the regulators of insulin secretion.
Step 3: Detailed Explanation:
Somatostatin inhibits the release of insulin.
It also inhibits glucagon and growth hormone.
Isoproterenol stimulates insulin release.
Propranolol is a beta-blocker.
Phentolamine is an alpha-blocker.
Thus, somatostatin inhibits insulin.
Step 4: Final Answer:
Somatostatin inhibits the release of insulin.
Hence, the correct option is (D).