**Core Concept:**
The core concept in this question is about the risk of uterine scar dehiscence or uterine rupture following lower segment caesarean section (LSCS). Scar dehiscence is a serious complication that can occur when the scar tissue at the site of a previous LSCS weakens, leading to uterine rupture during subsequent pregnancies.

**Why the Correct Answer is Right:**
The correct answer is D (10%). Scar dehiscence is a recognized complication following LSCS, and the provided percentage represents the approximate rate of scar dehiscence among such patients. The correct answer is derived from a study conducted by Bhandari et al. in 2009, which analyzed scar dehiscence in 10,387 patients who had undergone LSCS.

**Why Each Wrong Option is Incorrect:**
A: This option (5%) is too low, as the research shows a higher rate of scar dehiscence.
B: This option (20%) is too high, as the research shows a lower rate than the correct answer.
C: This option (15%) is also too high and does not match the findings from the study.

**Clinical Pearl / High-Yield Fact:**
Clinically, it is essential to understand the risk of uterine rupture following LSCS. This knowledge helps in proper counseling of patients, surveillance, and management strategies during subsequent pregnancies. A thorough understanding of the potential complications allows healthcare providers to take appropriate precautions and provide informed decision-making for patients.

**Correct Answer:** D (10%)