**Core Concept**
Triage is a process used in emergency and disaster situations to prioritize medical care based on the severity of injuries or illnesses, ensuring that those with life-threatening conditions receive immediate attention.

**Why the Correct Answer is Right**
Triage involves a systematic assessment of patients to identify those who require immediate treatment, those who can be treated later, and those who are unlikely to survive despite treatment. This process helps allocate limited medical resources effectively, maximizing the chances of saving lives. The principles of triage are based on the classification of patients into categories such as immediate, delayed, and expectant, depending on their condition.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because triage is not solely focused on treating patients in a hospital setting. While it may occur in a hospital, triage is a broader concept applicable in various emergency situations.

**Option B:** This option is incorrect because triage does not involve rationing medical care based on a patient's social status or economic condition. It is a medical decision-making process aimed at optimizing outcomes, not a means of allocating resources unfairly.

**Option C:** This option is incorrect because triage is not a diagnostic tool. It is a process of categorizing patients based on the severity of their condition, not a method of determining the underlying cause of their illness or injury.

**Clinical Pearl / High-Yield Fact**
In a triage scenario, the principle of "save as many as possible" should guide decision-making, with the aim of maximizing the number of lives saved while ensuring that those with life-threatening conditions receive immediate attention.

**Correct Answer: C. Triage is a process used in emergency and disaster situations to prioritize medical care based on the severity of injuries or illnesses, ensuring that those with life-threatening conditions receive immediate attention.**