**Core Concept**
Bolam's test is a legal precedent used to determine whether a doctor has acted reasonably in a medical negligence case. It assesses whether a doctor's actions were in line with the practice of a responsible body of medical professionals in the same circumstances.

**Why the Correct Answer is Right**
Bolam's test focuses on the professional standard of care, rather than a strict adherence to guidelines or protocols. It considers the opinion of a responsible body of medical professionals, taking into account the prevailing medical practice at the time. This approach aims to balance patient safety with the need for medical professionals to exercise their professional judgment.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Bolam's test is not primarily concerned with the doctor-patient relationship or the patient's autonomy.
**Option B:** This option is incorrect because Bolam's test does not focus on the doctor's adherence to hospital policies or protocols.
**Option C:** This option is incorrect because Bolam's test is a legal precedent, not a medical guideline or a standard of care set by a regulatory body.

**Clinical Pearl / High-Yield Fact**
To pass medical negligence cases, doctors must demonstrate that their actions were in line with the practice of a responsible body of medical professionals. This approach acknowledges that medical practice is not always black and white, and allows for professional judgment in complex cases.

**Correct Answer: D. Bolam's test is used in medical negligence cases to determine whether a doctor has acted reasonably.**