Which of the following best explain why the lower course of a river is sometimes choked with sediments?_x000D_ 1. The valley of a river is widest in its lower course._x000D_ 2. The velocity of a river in its lower course is low. 3. The delta sometimes develops in a river's lower course_x000D_ 4. Much of the river water is drawn for irrigation in the lower course._x000D_ Select the correct answer using the code given below:

• A. 1, 2, 3 and 4
• B. 1, 3 and 4 only
• C. 2 and 4 only
• D. 1, 2 and 3 only