• Preservation Principle of High Salt and Sugar Concentrations:
• Osmotic Dehydration & Water Activity ($a_w$):
• High concentrations of solutes (salt in pickling $\gt 15\%$, sugar in jams/jellies $\gt 65\%$) create a hypertonic extracellular environment.
• Plasmolysis: Osmotic pressure draws cellular water out of contaminating microbial cells through their semi-permeable cell membranes, shrinking the cytoplasm.
• This sharply lowers free water activity ($a_w \lt 0.60 - 0.75$), depriving bacteria, yeasts, and molds of the moisture essential for enzymatic metabolism and vegetative growth.
• Conclusion: reduce the availability of water for the microorganisms to grow (Option 2).

Correct option: (2) reduce the availability of water for the microorganisms to grow