Explanation:

- Chhatrapati Shivaji was the founder of the Maratha Empire in western India.

- Soyarabai was one of Shivaji's wives.

- Narayan is not the name of their son.

- Shahaji was Shivaji's father, not his son with Soyarabai.

- Sharnbhaji is not a historical figure related to Shivaji in this context.

- Rajaram was indeed the son of Chhatrapati Shivaji and Soyarabai.

Rajaram was the younger son and played a significant role in Maratha history after Shivaji’s death.

- Correct Answer: Option 4 - Rajaram