The correct answer is (c) Bhagirathi.
The Bhagirathi is the longest river in Uttarakhand, India. It is a tributary of the Ganges River. The Bhagirathi originates in the Garhwal Himalayas, near the Nanda Devi peak. It flows through the Garhwal region of Uttarakhand, and joins the Alaknanda River at Devprayag to form the Ganges River.
The Kosi is a river in Nepal and India. It is the longest river in Nepal, and the fifth longest river in India. The Kosi originates in the Himalayas, and flows through the plains of Nepal and India. It joins the Ganges River at the confluence of the Ganges and the Yamuna rivers.
The Kali is a river in Nepal and India. It is the longest river in the Kumaon region of Uttarakhand. The Kali originates in the Himalayas, and flows through the Kumaon region of Uttarakhand, and joins the Saryu River at Pancheswar.
The Saryu is a river in India. It is the longest river in the Kumaon region of Uttarakhand. The Saryu originates in the Himalayas, and flows through the Kumaon region of Uttarakhand, and joins the Ganges River at Allahabad.