**Core Concept**
In forensic proceedings, the right to cross-examine witnesses is a fundamental aspect of due process, ensuring the reliability and credibility of evidence. This right is exercised by the party opposing the prosecution, specifically the defence, to challenge the witness’s testimony.

**Why the Correct Answer is Right**
Cross-examination is a legal procedure where the defence counsel directly questions the prosecution witness to test the accuracy, consistency, and reliability of their testimony. This process allows the defence to expose contradictions, assess witness bias, or highlight inconsistencies in facts or memory. Under criminal procedure, only the defence has the statutory right and responsibility to conduct cross-examination, as per the principles of fair trial and adversarial justice.

**Why Each Wrong Option is Incorrect**
Option A: The public prosecutor does not conduct cross-examination; their role is to present evidence and examine witnesses on behalf of the state, not to challenge the prosecution’s own witnesses.
Option C: The judge does not conduct cross-examination; their role is to oversee the process, ensure legal propriety, and maintain order, but not to question witnesses.
Option D: Cross-examination is a mandatory and permitted legal right, so it is not "none" — it is actively performed by the defence.

**Clinical Pearl / High-Yield Fact**
In criminal trials, the defence counsel has exclusive authority to cross-examine prosecution witnesses — this is a cornerstone of adversarial justice and protects against unwarranted or unverified claims.

✓ Correct Answer: B. Defence counsel