In Time, Bread Becomes Stale and Grows Mold on the Exposed

In time, bread becomes stale and grows mold on the exposed surfaces. Why does mold not begin growing inside the bread loaf?

A) Mold can grow only on dry surfaces.
B) Only molds at the surface of the bread can get oxygen to respire.
C) Mold actually begins from anywhere inside but produces colored spores only at the surface.
D) There is an antibiotic antagonism between the bread mold and the internal yeasts that made the bread rise.
E) The bread was sterilized when it was baked and thereafter mold spores from the air settle only on the outside of the cooled bread.