During Periods of Fasting, Why Is Fat Said to Have

During periods of fasting, why is fat said to have a protein-sparing effect?

A) The body oxidizes its spare protein before it depletes its fat reserves.
B) The body metabolizes fats and proteins through the same metabolic pathways.
C) The body must have an adequate fat intake in order to absorb and metabolize proteins.
D) The body must have an adequate protein intake in order to absorb and metabolize fats.
E) The body does not oxidize its proteins unless it has consumed its fat reserves first.