Explanation:

- Option 1: Santosh Yadav - She is a renowned Indian mountaineer, known for being the first woman to successfully climb Mount Everest twice, but not the youngest man to scale the seven highest peaks and volcanic summits.

- Option 2: Satyarup Siddhanta - He is an accomplished mountaineer from India who has indeed become the youngest man to scale both the seven highest peaks on each continent and the volcanic summits.

- Option 3: Raj Singh Dharmashaktu - He is another distinguished Indian mountaineer with multiple Everest ascents but not known for the achievement in question.

- Option 4: Mohan Singh - There is no widely known mountaineer by this name associated with the described achievement.