**Core Concept**
The concept of triage is a fundamental principle in disaster management, where patients are categorized based on their urgency of treatment to optimize resource allocation. In this context, a color-coded system is used to quickly identify patients who require immediate medical attention, those who can wait, and those who are unlikely to survive regardless of treatment.

**Why the Correct Answer is Right**
In the triage system, green-colored patients are those who are ambulatory and have minor injuries. They are able to walk and do not require immediate medical attention. This category includes patients who are stable and can be treated in a non-emergency setting. Green patients are often referred to as "walking wounded" and are prioritized for treatment after more critical patients have been stabilized.

**Why Each Wrong Option is Incorrect**
**Option A:** Red patients are those who require immediate medical attention and are often critically injured. They are the highest priority in the triage system and are typically treated first.
**Option B:** Yellow patients are those who require observation and treatment, but are not critically injured. They are often patients with minor to moderate injuries who require monitoring and stabilization.
**Option D:** Black patients are those who are deceased or have injuries that are so severe that they will not survive regardless of treatment. They are not ambulatory and are not prioritized for treatment.

**Clinical Pearl / High-Yield Fact**
In disaster situations, the triage system helps healthcare providers prioritize patients based on their level of need, ensuring that those who are most critically injured receive timely treatment. This system also helps to conserve resources and optimize the use of limited medical supplies.

**✓ Correct Answer: C. Green. Ambulatory patients after a Disaster are categorized into Green colour of Triage.**