The following detects infrared energy (heat):

Options

A. chemoreceptors
B. photoreceptors
C. mechanoreceptors
D. thermoreceptors

Explanation

To determine which type of receptor detects infrared energy (heat), we can analyze each of the given options step by step:

1. **Identify the options**: The options provided are:
- Chemoreceptors
- Photoreceptors
- Mechanoreceptors
- Thermoreceptors

2. **Analyze Chemoreceptors**:
- Chemoreceptors are specialized receptors that respond to chemical stimuli. They detect changes in chemical concentrations (like taste and smell).
- **Hint**: Think about what type of stimuli these receptors respond to.

3. **Analyze Photoreceptors**:
- Photoreceptors are sensitive to light. They are involved in vision and respond to visible light wavelengths.
- **Hint**: Consider what type of energy these receptors are designed to detect.

4. **Analyze Mechanoreceptors**:
- Mechanoreceptors respond to mechanical forces such as pressure, vibration, and touch. They are not involved in detecting temperature.
- **Hint**: Reflect on the physical forces these receptors are sensitive to.

5. **Analyze Thermoreceptors**:
- Thermoreceptors are specialized receptors that detect changes in temperature. They can sense both heat and cold.
- **Hint**: Remember that heat is a form of energy related to temperature.

6. **Conclusion**:
- Based on the analysis, thermoreceptors are the receptors that detect infrared energy (heat). Therefore, the correct answer is **thermoreceptors**.

### Summary of Steps:
1. Identify the options.
2. Analyze each receptor type (chemoreceptors, photoreceptors, mechanoreceptors).
3. Identify the function of thermoreceptors.
4. Conclude that thermoreceptors detect infrared energy (heat).