The important tributary of Markanda river is ……….. .

The correct answer is: B. Tangri.

The Tangri River is a tributary of the Markanda River in the Indian state of Haryana. It originates in the Shivalik Hills near the village of Tangri in the district of Yamunanagar. The river flows in a northerly direction and joins the Markanda River near the village of Pipli in the district of Kurukshetra. The Tangri River is a perennial river and its water is used for irrigation and drinking water.

The other options are incorrect because:

• Sahibi River is a tributary of the Yamuna River.
• Krishnavati River is a tributary of the Chambal River.
• Dohan River is a tributary of the Ravi River.