*Question E4D06:
What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?*  

*Correct Answer is  C: Desensitization*  

### AI Response: (may contain errors)  

The correct answer to the question is **C: Desensitization**. 

### Explanation of the Correct Answer:
- **Desensitization** refers to the reduction in a receiver's sensitivity due to the presence of a strong signal close to the frequency of the desired signal. This strong signal can cause the receiver to become less responsive to weaker signals, making it difficult to pick up the intended transmission.

### Why the Other Choices are Incorrect:
- **A: Reciprocal mixing**  
  This phenomenon occurs when two signals mix in a non-linear device, creating unwanted signals at frequencies that can interfere with the desired signal. It is not specifically about the reduction in sensitivity due to a strong nearby signal.

- **B: Quieting**  
  Quieting refers to the reduction of noise in a receiver when a strong signal is present. While it can improve the signal-to-noise ratio, it does not describe the reduction in sensitivity itself.

- **D: Cross modulation interference**  
  This occurs when a strong signal modulates the amplitude of another signal, causing interference. It is related to interference but does not specifically address the reduction in sensitivity of the receiver.

### Summary:
- **Desensitization** is the correct term for the reduction in receiver sensitivity caused by a strong signal near the received frequency. Understanding this concept is crucial for recognizing how strong signals can impact the performance of a receiver in amateur radio operations.