The correct answer is: A. Yamuna and Markanda.
The Piedmont Plains in Haryana is a region of alluvial plains that lies in the foothills of the Himalayas. The region is drained by the Yamuna River and its tributaries, including the Markanda River. The Yamuna River is a major river in India that flows through the states of Haryana, Uttar Pradesh, and Delhi. The Markanda River is a tributary of the Yamuna River that flows through the states of Haryana and Punjab.
The Piedmont Plains in Haryana is a fertile region that is used for agriculture. The region is also home to a number of industrial and urban centers, including the city of Chandigarh.
The other options are incorrect because they do not drain the Piedmont Plains in Haryana. The Saraswati River is a mythical river that is said to have dried up thousands of years ago. The Ghaggar River is a seasonal river that flows through the states of Haryana, Punjab, and Rajasthan. The Chautang River is a tributary of the Ghaggar River.