**Core Concept**
Testosterone is a potent androgen hormone that plays a crucial role in the development and maintenance of male reproductive tissues, secondary sex characteristics, and bone density. Prolonged exposure to high levels of testosterone can disrupt the body's natural balance and lead to various adverse effects.

**Why the Correct Answer is Right**
Continuous testosterone administration can lead to a condition known as androgenic alopecia, also referred to as male pattern baldness. This occurs due to the conversion of testosterone to dihydrotestosterone (DHT) by the enzyme 5-alpha-reductase. DHT binds to androgen receptors in the scalp, leading to the miniaturization of hair follicles and eventual hair loss.

**Why Each Wrong Option is Incorrect**
**Option A:** While testosterone can affect the prostate, it is not the primary cause of benign prostatic hyperplasia (BPH).
**Option B:** Testosterone replacement therapy is actually used to treat hypogonadism, not hypothyroidism.
**Option C:** Although testosterone can increase muscle mass, it does not directly cause muscle cramps.

**Clinical Pearl / High-Yield Fact**
It's essential to note that androgenic alopecia is a common side effect of long-term testosterone therapy, and patients should be monitored for signs of hair loss.

**Correct Answer:** C.