_____reduces melatonin formation.

Options

A. Temperature
B. Humidity
C. Light
D. Pressure

Answer

To answer the question "_____ reduces melatonin formation," we need to identify the factor that inhibits the production of melatonin, a hormone secreted by the pineal gland.

### Step-by-Step Solution:

1. **Understanding Melatonin**:
- Melatonin is a hormone produced by the pineal gland, which is located in the forebrain.
- Its primary function is to regulate the sleep-wake cycle, also known as the circadian rhythm.

2. **Factors Affecting Melatonin Production**:
- Various environmental factors can influence the secretion of melatonin.
- Among these factors, light exposure is particularly significant.

3. **Role of Light**:
- Light exposure, especially blue light, inhibits the production of melatonin.
- When we are exposed to light, particularly in the evening or before bedtime, it signals the body to stay awake and reduces melatonin levels.

4. **Conclusion**:
- Given the options: A) temperature, B) humidity, C) light, and D) pressure, the factor that reduces melatonin formation is **C) light**.

### Final Answer:
C) light

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