Answer: 1) On the bus ride to his school.
Explanation: There is no action, or saying what happened on the bus ride. Only the subject is given (the bus ride)
Verb is your answer, it describes an action such as (running, jumping, laughing...)
The correct word is who. Because, The sentence "I like people who sing" makes more sense then "I like people whom sing"
Hope I helped!
- Amber