Waterfalls may be formed in the following ways except a. When a bar of resistant rock lies transversely across a river valley b. When a river plunges...

Waterfalls may be formed in the following ways except

a. When a bar of resistant rock lies transversely across a river valley

b. When a river plunges down the edge of a plateau

c. When a river descends a hanging valley

d. When river capture occurs at the head of a stream