When immersed in a beaker of water, a straight glass rod seems to undergo bending, as depicted in the diagram.
glass rod/
air/
water/
What provides the most accurate explanation for this phenomenon?
a. The temperature of the water in the beaker is higher than that of the surrounding air.
b. As light crosses the boundary between air and water, it undergoes refraction.
c. In water, light moves at a higher speed compared to its velocity in air.
d. At the interface between air and water, light undergoes reflection.