The builders would make stacks of stone steps on top of each other to create the stairs. The bank of steps lined the walls. On days when the stepwells were full, people went down only a step or two. On other days, they stepped all the way down to the bottom! Complete the chart. What does "bank" mean in this passage?

A. a material for connecting rocks.

B. a pile of something.

C. a covering for keeping water out.

D. a structure built below the surface.​