## Core Concept
The question tests understanding of the anatomy of the anterior abdominal wall and the superficial perineal space, specifically the fascial planes through which extravasated urine can track. The layers of the anterior abdominal wall, from superficial to deep, include the skin, superficial fascia (Camper's fascia), deep fascia (Scarpa's fascia), and the rectus abdominis muscle within its sheath.

## Why the Correct Answer is Right
Extravasated urine from the superficial perineal space can track upwards into the anterior abdominal wall. The superficial perineal space is bounded inferiorly by the perineal membrane (inferior fascia of the urogenital diaphragm) and communicates with the potential spaces of the abdominal wall. When urine enters the anterior abdominal wall, it passes deep to the superficial fascia (Camper's fascia) but superficial to Scarpa's fascia. Scarpa's fascia is a deeper, membranous layer of the superficial fascia that is more closely adherent to the deeper structures. Therefore, urine would be found immediately deep to Scarpa's fascia.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because the question asks for the layer immediately superficial to where the urine is found.
- **Option B:** This option suggests a deeper layer; however, urine tracking from the superficial perineal space would not initially be deep to the external oblique aponeurosis.
- **Option C:** This option refers to a deeper muscle layer; urine would not be immediately deep to the skin when tracking from the superficial perineal space into the abdominal wall.
- **Option D:** This option suggests the transversalis fascia, which is deeper than Scarpa's fascia and not the immediate layer.

## Clinical Pearl / High-Yield Fact
A clinically relevant point is that extravasated urine or fluid tracking from the perineum into the abdominal wall will be found in the superficial fascial space, which is between the superficial fascia (Camper's fascia) and Scarpa's fascia. This can influence the spread of infection or fluid collections.

## Correct Answer: B. Scarpa's fascia.