**Core Concept**
The boy's symptoms and physical examination findings are indicative of an abnormality in the development of the urethra, specifically epispadias or hypospadias. These conditions are characterized by the urethral meatus being located on the dorsal or ventral side of the penis, respectively. The most common type of abnormality seen in this boy is hypospadias, which affects approximately 1 in 200 male births.

**Why the Correct Answer is Right**
Hypospadias is a congenital anomaly where the urethral meatus is located on the underside of the penis, proximal to the tip of the glans penis. This occurs due to incomplete closure of the urethral folds during fetal development. The urethral folds normally fuse to form the penile urethra, but in hypospadias, this process is incomplete, resulting in the urethral meatus being located on the ventral side of the penis. This condition can be associated with other genitourinary anomalies and may require surgical correction.

**Why Each Wrong Option is Incorrect**
**Option A:** Epispadias is a less common condition where the urethral meatus is located on the dorsal side of the penis. While epispadias is a possible diagnosis, it is not the most common type of abnormality seen in this boy.
**Option B:** Phimosis is a condition where the foreskin is too tight to retract over the glans penis. This condition does not affect the location of the urethral meatus and is not the correct diagnosis in this case.
**Option C:** Urethral stricture is a narrowing of the urethra, usually due to scarring or injury. This condition can cause difficulty in directing the urinary stream but is not a congenital anomaly and is not the correct diagnosis in this case.

**Clinical Pearl / High-Yield Fact**
Hypospadias is the most common congenital anomaly of the genitourinary system in males, with a reported incidence of approximately 1 in 200 male births. It is essential to diagnose and treat hypospadias early to prevent complications such as urinary tract infections and to improve cosmetic and functional outcomes.

**Correct Answer:** D.