Sorbic acid and its salts are useful against—

Correct option is D

• Sorbic acid and potassium sorbate are widely used food preservatives that effectively inhibit the growth of yeasts and molds, making them useful in bakery products, cheeses, beverages, and fruit-based foods.
• Their antimicrobial effect is strongest in acidic conditions, where sorbic acid remains in its undissociated form and can penetrate microbial cell membranes, disrupting metabolism.
• Sorbates are not highly effective against bacteria, especially Gram-negative bacteria, which is why options (a) and (b) are incorrect.
• Option (c) is incomplete because sorbates inhibit both molds and yeasts—not molds alone.