**Core Concept**
The storage of expressed breast milk requires careful consideration to prevent bacterial contamination and preservation of its nutritional and immunological properties. Room temperature storage is a specific condition that affects the shelf life of breast milk.

**Why the Correct Answer is Right**
Breast milk can be safely stored at room temperature (around 25°C or 77°F) for up to 6 hours. This is because the risk of bacterial contamination is relatively low within this time frame. However, it's essential to note that the milk should be kept away from direct sunlight, heat sources, and moisture. The ideal storage temperature for breast milk is between 2°C and 4°C (36°F to 39°F), but when this is not feasible, room temperature storage can be an acceptable alternative.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because there is no established safe storage time for breast milk at room temperature beyond 6 hours.
**Option B:** This option is incorrect because it suggests a storage time that is too long, increasing the risk of bacterial contamination.
**Option C:** This option is incorrect because it does not provide a specific time frame, making it an ambiguous and unreliable choice.

**Clinical Pearl / High-Yield Fact**
When storing breast milk at room temperature, it's crucial to label the container with the time it was expressed and the storage temperature to ensure safe handling and consumption.

**Correct Answer: C. 6 hours**