## **Core Concept**
The question tests knowledge of the urogenital system, specifically the bulbourethral glands (also known as Cowper's glands) and their anatomical relationship with surrounding structures. The bulbourethral glands are a pair of small glands in the male reproductive system that secrete a clear fluid into the urethra.

## **Why the Correct Answer is Right**
The bulbourethral glands are located on either side of the membranous part of the urethra, and they drain into the spongy (penile) urethra. An infection of these glands can lead to inflammation and symptoms such as fever, nausea, and localized discomfort or itching. Given their anatomical location, an infection of the bulbourethral glands would most likely affect the **spongy urethra**, as this is where they drain.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because the infection of bulbourethral glands primarily affects the urethra, specifically where these glands drain, which is not directly related to the prostatic urethra.
- **Option B:** This option might seem plausible due to the proximity of the seminal vesicles to other parts of the male reproductive system, but they are not directly related to the drainage or function of the bulbourethral glands.
- **Option D:** The epididymis is involved in the storage and maturation of sperm and is not directly related to the urethra or the function of the bulbourethral glands.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the bulbourethral glands play a role in the pre-ejaculate fluid, which helps to lubricate the urethra for sperm to pass through during ejaculation. Infection of these glands, though less common, can cause significant discomfort and urinary symptoms.

## **Correct Answer:** C.