Where a river flows from an area of harder rock to an area of softer rock, the softer rock may wear away, eventually forming a drop called a(n)
a.
oxbow lake.
b.
gully.
c.
waterfall.
d.
delta.

The right option is; c. waterfall

A waterfall is a river or other water bodies in which its water fall over the edge of a steep, high cliff on mountains, and falls vertically into a pool underneath. Waterfalls are usually formed when a river is still small especially in areas where softer rocks are below harder rocks. The process of erosion is highly important in the formation of waterfalls.

the answer is b)3/8x+1