The correct answer is: C. Shyok
The Nubra River is a tributary of the Shyok River, which in turn is a tributary of the Indus River. The Nubra River originates in the Karakoram Mountains and flows through the Nubra Valley in Ladakh, India. It merges with the Shyok River near Diskit, Ladakh.
The Jhelum River is a tributary of the Chenab River, which in turn is a tributary of the Indus River. The Jhelum River originates in the Pir Panjal Range and flows through the Kashmir Valley in Jammu and Kashmir, India. It does not merge with the Nubra River.
The Ravi River is a tributary of the Chenab River, which in turn is a tributary of the Indus River. The Ravi River originates in the Himalayas and flows through the Punjab region of India and Pakistan. It does not merge with the Nubra River.
The Tawi River is a tributary of the Chenab River, which in turn is a tributary of the Indus River. The Tawi River originates in the Pir Panjal Range and flows through the Jammu region of India. It does not merge with the Nubra River.