Correct Answer: Option A - 2 & 3 only
The Indus has a steep gradient and flows rapidly in its lower course.
This statement is incorrect. The Indus River has a steep gradient in its upper course where it flows through mountainous regions. In its lower course, it actually has a gentle gradient and flows slowly across the plains, forming a large delta before emptying into the Arabian Sea.
The Jhelum, Chenab, Ravi, Beas, and Sutlej join Indus near Mithankot.
This statement is correct. These five rivers, which are also known as the Punjab rivers (Punjab means "land of five rivers"), join together and eventually merge with the Indus River near Mithankot in Pakistan.
The Indus emerges from the mountains at Attock.
This statement is correct. The Indus River emerges from the Himalayan mountains and enters the plains at Attock in Pakistan. This is a significant geographical transition point for the river.