Explanation:

- Option 1: Transverse waves

- These waves oscillate perpendicular to the direction of wave travel.

- Example: Light waves.

- Not applicable to sound in air.

- Option 2: Longitudinal waves

- In these waves, oscillations occur in the same direction as wave travel.

- Sound waves in air compress and rarefy the air.

- Correct answer.

- Option 3: May be both types

- A wave cannot be both types simultaneously in the same medium.

- Air supports only longitudinal waves for sound.

- Option 4: None of the above

- Incorrect as sound waves in air follow one type.