**Core Concept**
Gynaecomastia refers to the benign enlargement of breast tissue in males, often due to an imbalance of **estrogen** and **androgen** hormones. This condition can be caused by various factors, including certain medications. **Pharmacological** agents that alter hormone levels can lead to gynaecomastia as a side effect.

**Why the Correct Answer is Right**
Since the correct answer is not provided, let's discuss the general principle. Medications that are known to cause gynaecomastia typically do so by either increasing **estrogen** levels, decreasing **androgen** levels, or interfering with the balance between these hormones. Examples include **spironolactone**, **ketoconazole**, and **anabolic steroids**.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option, we can't comment directly, but typically, any medication that significantly alters **hormone balance** could potentially be incorrect if it's known to cause gynaecomastia.
**Option B:** Similarly, without specifics, we look for medications or factors not associated with **hormonal imbalance** or those that are known to prevent gynaecomastia.
**Option C:** This option would be incorrect if it represents a drug or condition known to induce gynaecomastia through **pharmacodynamic** or **pharmacokinetic** interactions affecting **sex hormones**.
**Option D:** Any option that does not fit the pattern of causing **hormonal disturbances** leading to gynaecomastia could potentially be the correct answer, but without specifics, it's challenging to determine.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that gynaecomastia can be a side effect of various medications, including those used to treat **prostate cancer**, **high blood pressure**, and **AIDS**. Recognizing the potential for drug-induced gynaecomastia is crucial for managing patient care and counseling.

**Correct Answer:** Correct Answer: D. Finasteride