Which medium is specifically used to test for lactose fermentation, glucose fermentation, and sulfide production?

Kligler's Iron Agar is specifically designed for testing lactose fermentation, glucose fermentation, and sulfide production in bacteria. This medium contains both lactose and glucose, allowing for the differentiation of organisms based on their ability to ferment these sugars. When a bacterium ferments glucose, it produces acid, which can result in a color change in the medium. If lactose is also fermented, a further change will occur, indicating the bacterium can utilize both carbohydrates.

Additionally, Kligler's Iron Agar contains iron salts and a pH indicator that allows for the detection of hydrogen sulfide production. If sulfur-reducing bacteria are present, they will produce hydrogen sulfide, which reacts with the iron salts to form a black precipitate, making it easy to identify organisms capable of sulfate reduction.

The other options do not serve the same specific purposes: phenol red broth is used for testing various sugar fermentations individually but does not test for sulfide production, nutrient agar is a general-purpose medium that does not provide specific information about sugar fermentation or sulfide production, and mannitol salt agar is primarily used to select for halophilic organisms and can only differentiate mannitol fermentation, not lactose or glucose fermentation.