When you travel in Himalayas, you will see the following:<br/>1. Deep gorges<br/>2. U-turn river courses<br/>3. Parallel mountain ranges<br/>4. Steep gradients causing land-sliding.<br/><br/>Which of the above can be said to be the evidence for Himalayas being young fold mountains?

1. Deep gorges — Correct. Himalayan rivers cut deep gorges because the mountains are still rising and rivers are actively downcutting; this is a classic sign of youthful topography.

2. U-turn river courses — Correct. Sharp bends/entrenched meanders and river deflections occur in tectonically active, rising mountains, indicating structural control and youthful relief.

3. Parallel mountain ranges — Correct. The Himalayas show a series of parallel ranges (Himadri, Himachal, Shiwalik), which is a structural feature of a young fold mountain system.

4. Steep gradients causing land-sliding — Correct. Steep unstable slopes, active erosion and frequent landslides are typical of geologically young fold mountains.

Hence, all four are evidence that the Himalayas are young fold mountains.