what interaction causes the water to spread as they pass through the rock opening?\nabsorption\ndiffraction\n…

Brief Explanations:

Diffraction is the bending and spreading of waves as they pass through an opening or around an obstacle. When water waves pass through a rock - opening, they spread out due to diffraction. Absorption is the process of a substance taking in another substance. Reflection is the bouncing back of waves from a surface. Refraction is the bending of waves as they pass from one medium to another with a different density.

Answer:

B. diffraction