How does Clostridium butylicum contribute to industry?

The correct answer is Option (2)- Ferments sugars to butyric acid

Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes. Examples of acid producers are Aspergillus niger (a fungus) of citric acid, Acetobacter aceti (a bacterium) of acetic acid; Clostridium butylicum (a bacterium) of butyric acid and Lactobacillus (a bacterium) of lactic acid. Yeast (Saccharomyces cerevisiae) is used for commercial production of ethanol. Microbes are also used for production of enzymes.

Clostridium butylicum is a bacterium used in the production of butyric acid, which has various industrial applications.