Okay, let's tackle this question about where the bulbourethral glands open into the urethra. First, I need to recall the anatomy of the male urethra and the associated glands. The main glands involved in the male reproductive system are the seminal vesicles, prostate gland, and bulbourethral glands.

The bulbourethral glands, also known as Cowper's glands, are paired structures. Their ducts open into the urethra. Now, the male urethra has several parts: the prostatic urethra, membranous urethra, and spongy (penile) urethra. The prostatic part is surrounded by the prostate gland, the membranous is the shortest and passes through the urogenital diaphragm, and the spongy part runs through the penis to the external urethral orifice.

The bulbourethral glands are located in the perineal region, and their ducts open into the spongy urethra, specifically near the beginning of the penile part. This is important because their secretions help neutralize acidity in the urethra before ejaculation.

Wait, but I need to be precise. The prostatic urethra is where the prostate opens, the membranous is the narrow part, and the bulbourethral glands open into the spongy urethra. So the answer should be the spongy (penile) part. Let me check some references. Yes, Cowper's glands open into the spongy urethra, just proximal to the glans penis. That makes sense because their secretions would lubricate the urethra and neutralize any acidic urine residue before seminal fluid passes through.

The incorrect options would likely be the prostatic or membranous parts. The prostate opens into the prostatic urethra, and the seminal vesicles also drain there. The membranous part is too short and doesn't have openings from the bulbourethral glands. So the correct answer is the spongy (penile) urethra. Let me make sure there's no confusion with the ejaculatory ducts. No, those open into the prostatic urethra. So the key point here is the bulbourethral glands open into the spongy part. Got it.

**Core Concept**
The bulbourethral glands (Cowper’s glands) are paired exocrine glands that secrete a clear, viscous fluid into the urethra. Their ducts open into the **spongy (penile) urethra**, specifically near the bulb of the penis, to lubricate and neutralize acidic urine residues before ejaculation.

**Why the Correct Answer is Right**
The bulbourethral glands open into the **spongy (penile) urethra**, which is the distal portion of the male urethra passing through the corpus spongiosum of the penis. Their secretions, released during sexual arousal, neutralize residual acidic urine and lubricate the urethra for semen passage. Anatomically, they are distinct from the prostate and seminal vesicles, which drain into the prostatic urethra.

**Why Each Wrong Option is Incorrect**
**Option A:** *Prostatic urethra* – This is where the prostate gland and ejaculatory ducts open,

✓ Correct Answer: B. Spongy