**Core Concept**
In primary health care (PHC) settings, proper disposal of placenta is crucial to prevent the spread of infections and maintain a clean environment. The disposal method should be in accordance with standard infection control practices and local regulations.

**Why the Correct Answer is Right**
The correct method of disposing placenta involves wrapping it in a plastic bag or a clean cloth, followed by incineration or autoclaving. This process ensures that the placenta is properly sterilized and disposed of, reducing the risk of infection transmission. In PHC settings, where resources may be limited, autoclaving or incineration may not always be feasible. In such cases, wrapping the placenta in a plastic bag and disposing of it in a designated biohazard waste container is the next best option.

**Why Each Wrong Option is Incorrect**
**Option A:** Placing the placenta in a sharps container is incorrect because sharps containers are designed for disposing of sharp objects like needles and syringes, not biological waste like placentas.

**Option B:** Burying the placenta in a garden or yard is incorrect because it poses a risk of infection transmission to other individuals who may come into contact with the buried placenta.

**Option C:** Disposing of the placenta in a regular trash can is incorrect because it does not ensure proper sterilization and may lead to the spread of infections.

**Clinical Pearl / High-Yield Fact**
When disposing of placenta, it's essential to remember that autoclaving or incineration is the preferred method. However, in the absence of these resources, wrapping the placenta in a plastic bag and disposing of it in a designated biohazard waste container is a safer alternative.

**Correct Answer: D.**