Select the most appropriate example of the denaturation of protein

Select the most appropriate example of the denaturation of protein.

A. Egg albumin, which is a translucent fluid, changes to opaque white solid after boiling.
B. Rice granules, which are smaller in size and translucent, appear larger and opaque white after cooking.
C. Oil, if kept for a longer time at room temperature, turns rancid and appears discolored.