**Core Concept**
Oligospermia refers to a condition characterized by a low sperm count in the ejaculate, often associated with male infertility. Certain medications can contribute to this condition by affecting testicular function, hormonal balance, or sperm production.

**Why the Correct Answer is Right**
Some drugs can cause oligospermia by interfering with the hypothalamic-pituitary-gonadal axis, leading to decreased production of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). This hormonal disruption can result in reduced testosterone production and impaired spermatogenesis. Specifically, drugs that affect the hypothalamic-pituitary axis or directly impair testicular function can lead to oligospermia.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the context of oligospermia.
* **Option B:** This option may cause other side effects, but it is not directly related to oligospermia.
* **Option D:** This option is incorrect because it is not associated with oligospermia.

**Clinical Pearl / High-Yield Fact**
Medications that cause oligospermia often do so by disrupting the delicate balance between the hypothalamus, pituitary gland, and testes. Familiarizing yourself with these medications and their effects on reproductive function is crucial for managing male infertility and avoiding iatrogenic causes of oligospermia.

**Correct Answer:** C. Cimetidine, a histamine H2-receptor antagonist, is known to cause oligospermia by inhibiting the hypothalamic-pituitary-gonadal axis, leading to reduced testosterone production and impaired spermatogenesis.