Introduction:
A vacuum circuit breaker is a type of circuit breaker that uses a vacuum as the interrupting medium for breaking and making the electrical circuit. It is commonly used in medium voltage applications due to its compact size, high reliability, and low maintenance requirements.

Voltage Range:
The correct answer is option 'B', which states that a vacuum circuit breaker can be used in the voltage range of 22-66 kV. Let's understand why this is the correct answer.

Explanation:
A vacuum circuit breaker is designed to handle a specific voltage range based on its construction and insulation properties. Here are the reasons why option 'B' is the correct answer:

1. Insulation Level: The insulation level of a vacuum circuit breaker is determined by its ability to withstand the voltage stress during the interruption of the circuit. The insulation system used in a vacuum circuit breaker is designed to handle a specific voltage range.

2. Medium Voltage Applications: Vacuum circuit breakers are commonly used in medium voltage applications, which typically range from 3.3 kV to 33 kV. This voltage range includes options 'A' (11-33 kV) and 'C' (22-33 kV).

3. Higher Voltage Capability: Vacuum circuit breakers are capable of interrupting higher voltages than the options 'A' and 'C' mentioned above. They can handle voltages up to 66 kV, as stated in option 'B' (22-66 kV).

4. Advantages of Vacuum Circuit Breakers: Vacuum circuit breakers offer several advantages over other types of circuit breakers, such as:

- Compact Size: Vacuum circuit breakers are compact in size, making them suitable for installations where space is limited.
- High Reliability: Vacuum interrupters are highly reliable and have a long operational life.
- Low Maintenance: Vacuum circuit breakers require minimal maintenance due to the absence of arc quenching media like oil or gas.
- Fast Operation: Vacuum circuit breakers have fast operating times, ensuring quick interruption of the electrical circuit.

Conclusion:
In conclusion, a vacuum circuit breaker can be used in the voltage range of 22-66 kV. This range is suitable for medium voltage applications and offers several advantages such as compact size, high reliability, low maintenance, and fast operation.