Ms. Knuth places a stick in a pond. When she looked down at the stick, it appeared to be broken or bent at the point where the stick entered the water. This was caused by:

a
Diffraction of light waves around the stick.
b
Reflection of light waves passing from air into water.
c
Refraction of light waves passing from air into water.
d
A refraction of light from the water.

c. Refraction of light waves passing from air into water.