Step 1: Understanding synthetic estrogen derivatives.
Synthetic estrogens are chemicals that mimic the action of estrogen in the body. Novestrol is a synthetic estrogen derivative, commonly used in hormonal treatments.
Step 2: Analyzing the options.
(A) Tegamet: Tegamet (cimetidine) is a histamine receptor antagonist, not an estrogen derivative.
(B) Norethindrone: Norethindrone is a synthetic progestin, not an estrogen.
(C) Novestrol: Correct — Novestrol is a synthetic estrogen derivative.
(D) Ranitidine: Ranitidine is a medication used to treat ulcers and reflux, not a synthetic estrogen.
Step 3: Conclusion.
The correct answer is (C) Novestrol.