**Core Concept**
The doctrine of Res ipsa loquitur is a legal principle that implies negligence based on the mere occurrence of an accident, without the need for direct evidence of fault. This principle is often applied in cases where a foreign object is left inside a patient's body during surgery, such as a swab.

**Why the Correct Answer is Right**
The doctrine of Res ipsa loquitur is applicable in this scenario because the act of leaving a swab in the abdomen is a clear indication of negligence on the part of the doctor. This doctrine is based on the idea that a person who leaves a foreign object inside another person's body is likely to have been negligent, as it would be unlikely for the object to have been left in place without some breach of duty. In this case, the patient's abdomen would not normally contain a swab, making it clear that some negligent act must have occurred.

**Why Each Wrong Option is Incorrect**
**Option A:** Respondeat superior is a doctrine that holds an employer liable for the actions of their employees. However, this doctrine is not applicable in this scenario as it does not directly address the issue of negligence in leaving a foreign object inside a patient's body.

**Option B:** Informed consent is a doctrine that requires healthcare providers to inform patients about the risks and benefits of a treatment before obtaining their consent. While informed consent is an important principle in medical ethics, it is not directly related to the issue of leaving a foreign object inside a patient's body.

**Option C:** Vicarious liability is a doctrine that holds one party liable for the actions of another party. This doctrine is not applicable in this scenario as it does not directly address the issue of negligence in leaving a foreign object inside a patient's body.

**Clinical Pearl / High-Yield Fact**
A key takeaway from this scenario is that the doctrine of Res ipsa loquitur implies negligence based on the mere occurrence of an accident, without the need for direct evidence of fault. This principle is often applied in cases where a foreign object is left inside a patient's body during surgery.

**Correct Answer:** C.