Sonar makes use of :

Options

A. infrasonic sound
B. ultrasound
C. ordinary sound
D. light

Explanation

### Step-by-Step Text Solution:

1. **Understanding Sonar**:
- Sonar stands for Sound Navigation and Ranging. It is a technique that uses sound propagation to navigate, communicate, or detect objects underwater.

2. **Function of Sonar**:
- The primary function of sonar is to detect objects underwater and determine their distance. This is crucial for navigation and safety, especially for ships and submarines.

3. **How Sonar Works**:
- Sonar emits sound waves (ultrasonic sound) into the water. When these sound waves hit an object, they bounce back (reflect) to the source.
- By measuring the time it takes for the sound waves to return, the distance to the object can be calculated using the speed of sound in water.

4. **Comparison with Radar**:
- While radar uses radio waves to detect objects in the air, sonar is more effective for underwater detection due to the properties of sound waves in water.

5. **Conclusion**:
- Therefore, sonar makes use of sound waves (specifically ultrasonic sound) for navigation and ranging to detect and locate objects underwater.