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 Kedarnath Temple. It flows through the Garhwal region of Uttarakhand, and joins the Alaknanda River near 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 near Bhagalpur, Bihar.
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 near Pancheswar, Nepal.
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 near Allahabad, Uttar Pradesh.