Which of the following best explain why the lower course of a river is sometimes choked with sediments?
1 The valley of a river is widest in its lower course
2. The velocity of a river in its lower course is low.
3. The delta sometimes develops in a river lower course
4. Much of the river water is drawn for irrigation in the lower course

Options

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