**Core Concept**
The question is testing the understanding of the pathophysiology of benign prostatic hyperplasia (BPH) and the mechanism of action of drugs used to treat it. Specifically, it is asking about a drug that reduces the static component of urinary obstruction, which is the obstruction caused by the enlarged prostate gland pressing against the urethra.

**Why the Correct Answer is Right**
The correct answer is a drug that works by reducing the size of the prostate gland, thereby reducing the static component of urinary obstruction. This type of drug is called a 5-alpha-reductase inhibitor (5-ARI). These drugs work by inhibiting the enzyme 5-alpha-reductase, which converts testosterone to dihydrotestosterone (DHT). DHT is a potent androgen that promotes the growth of the prostate gland. By reducing the levels of DHT, 5-ARIs cause a reduction in prostate size, which takes several months to achieve. This reduction in prostate size leads to an improvement in urinary symptoms.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not a 5-ARIs, which are the primary class of drugs that reduce the static component of urinary obstruction in BPH.
* **Option B:** This option is not a correct example of a drug that reduces the static component of urinary obstruction in BPH. It may be a drug that treats other symptoms of BPH, but it is not the correct answer.
* **Option C:** This option is not a correct example of a drug that reduces the static component of urinary obstruction in BPH. It may be a drug that treats other conditions, but it is not the correct answer.
* **Option D:** This option is not a correct example of a drug that reduces the static component of urinary obstruction in BPH. It may be a drug that treats other symptoms of BPH, but it is not the correct answer.

**Clinical Pearl / High-Yield Fact**
5-ARIs, such as finasteride and dutasteride, are the primary class of drugs that reduce the static component of urinary obstruction in BPH. They are effective in reducing the size of the prostate gland and improving urinary symptoms, but they take several months to achieve their full effect.

**Correct Answer:** C. Finasteride.