The correct answer is: A. Pabbar
The Pabbar River is a tributary of the Tons River in the Indian states of Uttarakhand and Himachal Pradesh. It originates in the Garhwal Himalayas and flows through the Chakrata district of Uttarakhand before joining the Tons River near the border of Uttarakhand and Himachal Pradesh.
The Patsari River is a tributary of the Pabbar River. It originates in the Garhwal Himalayas and flows through the Chamoli district of Uttarakhand.
The Asni River is a tributary of the Tons River. It originates in the Garhwal Himalayas and flows through the Dehradun district of Uttarakhand.
The Giri River is a tributary of the Yamuna River. It originates in the Garhwal Himalayas and flows through the Dehradun district of Uttarakhand.