Answer:
C) salt enters microorganisms causing them to dry out and shrivel
Step-by-step explanation:
Salt drains water out of cells through osmosis. Basically, water moves across a cell membrane, since it tries to equalize the salt concentration on both sides of the membrane. The more salt you add, the more water will be removed from a cell, therefore for it will be harder for it to stay alive or reproduce.
High concentration of salt kills microorganisms that decay food - and eventually may cause disease. 20% salt concentration kills bacteria. Lower concentrations avoid to a certain extent microbial growth until you get down to the cells' salinity of the cells - which might cause the opposite: providing ideal reproducing conditions.