Explanation:

The correct answer is option B: Aspergillus niger - butyric acid.

Saccharomyces - Ethanol:
Saccharomyces is a type of yeast that is commonly used in the fermentation process to produce ethanol. It is a single-celled fungus that can convert sugars into ethanol and carbon dioxide through the process of anaerobic respiration. This makes it a key organism in the production of alcoholic beverages like wine, beer, and spirits.

Monascus - Yeast:
Monascus is a genus of fungi that is commonly used in the production of fermented foods and beverages. It is often referred to as "red yeast" due to its characteristic red pigment. Monascus species are used to ferment rice and soybeans to produce various products, including red yeast rice, which is used as a food coloring and natural medicine.

Cholera - Vibrio:
Cholera is an infectious disease caused by the bacterium Vibrio cholerae. Vibrio cholerae is a gram-negative, comma-shaped bacterium that infects the small intestine, leading to severe diarrhea and dehydration. Cholera is primarily spread through contaminated water and food, and it can cause epidemics in areas with poor sanitation and hygiene.

Aspergillus niger - Butyric acid:
Aspergillus niger is a common fungus that is known for its ability to produce various organic acids, enzymes, and other metabolites. However, it does not produce butyric acid. Butyric acid is a short-chain fatty acid that is typically produced by bacteria, particularly those found in the gut. It is involved in various physiological processes and has important roles in energy metabolism.

Therefore, the mismatched option is B: Aspergillus niger - butyric acid, as Aspergillus niger does not produce butyric acid.