It Seems That Bacteria and Molds Should Grow Well in Jam

It seems that bacteria and molds should grow well in jam. It's extremely high in sugar, a substance cells typically use for energy, and contains enough other nutrients to support cell growth. Yet jam can be left unrefrigerated for a very long time without contamination by microorganisms. How can this be?

A) Bacteria and molds cannot grow on fruit products.
B) The high sugar concentration causes bacterial and mold cells to swell and rupture.
C) The high sugar concentration damages cell membranes.
D) Bacteria and molds cannot get into the jam because its high concentration of sugar makes it so sticky.
E) The high sugar concentration causes bacterial and mold cells to shrink and die.