Anna took a large, jagged rock down to the river near her home and placed it in the water where the water was moving very fast. She went back to check the rock several months later. What changes will Anna observe in her rock?

a
The rock will be smaller and smooth, as jagged edges were worn by the water.
b
The rock will be larger and smooth, as small pieces were added by the water.
c
The rock will be larger and rough, as other minerals were added by the water.
d
The rock will smaller and rough, as pieces were ripped off by the water.