*Question G7C01:
What circuit is used to select one of the sidebands from a balanced modulator?*  

*Correct Answer is  B: Filter*  

### AI Response: (may contain errors)  

To select one of the sidebands from a balanced modulator, a filter is used. 

### Explanation of the Correct Answer:
- **Correct Answer: Filter**
  - A filter is designed to allow certain frequencies to pass while blocking others. In the context of a balanced modulator, it is used to isolate either the upper or lower sideband from the modulated signal. This is essential in single-sideband (SSB) communication, where only one sideband is transmitted to improve efficiency and reduce bandwidth.

### Explanation of Incorrect Answers:
- **A: Carrier oscillator**
  - The carrier oscillator generates the carrier frequency but does not select sidebands. Its role is to provide the frequency that is modulated by the audio signal.

- **C: IF amplifier**
  - The intermediate frequency (IF) amplifier amplifies signals at a specific frequency after mixing but does not perform sideband selection. It is used in superheterodyne receivers to improve signal strength.

- **D: RF amplifier**
  - The RF amplifier boosts the radio frequency signals but does not differentiate between sidebands. Its purpose is to increase the power of the RF signal before transmission or after reception.

### Summary:
- A filter is essential for selecting one sideband in SSB communication, while the other options serve different functions in the modulation and amplification process. Understanding the roles of these components is crucial for grasping the principles of radio communication.