**Core Concept**
The question tests knowledge of **paediatric non-accidental injury (NAI)** markers, which are crucial for identifying child abuse. **Child protection** and **safeguarding** are key aspects of paediatric care, requiring healthcare professionals to recognize signs of non-accidental injury.

**Why the Correct Answer is Right**
Common markers of paediatric NAI include injuries with inconsistent histories, multiple injuries at different stages of healing, and specific injury patterns such as **bruises on non-mobile infants**, **burns with clear boundaries**, and **fractures without a plausible explanation**. These signs suggest intentional harm rather than accidental injury.

**Why Each Wrong Option is Incorrect**
**Option A:** Inadequate or vague, as specific markers are needed for diagnosis.
**Option B:** Insufficient, as it may not encompass all types of NAI.
**Option C:** Incorrect, as it may not be directly related to NAI.
**Option D:** Not provided, but typically, options without specific injury patterns are incorrect.

**Clinical Pearl / High-Yield Fact**
Remember that **any injury** in a non-mobile infant is suspicious and warrants further investigation, as these children are unable to inflict such injuries on themselves. Always consider the possibility of NAI when evaluating paediatric injuries.

**Correct Answer:** Not provided in the question, but common markers include bruises, burns, and fractures with inconsistent histories.