Question

Select all of the food items where microbial growth is controlled by means of osmotic pressure.

Answer 1

The answer would be:
Jellies
Salt cured meats
Honey

High osmotic pressure can be used as a natural preservative. In high osmotic pressure, the microbes will hardly survive as their surrounding concentration is too high and induce severe osmosis. The osmosis will take the microbes water, makes it shrink continually lead to the microbes death. 
In those 3 foods, there is a high concentration of sugar or salt that increase the osmotic pressure.