Big holes in Swis A. a machine

B. a bacterium that produces methane gas

C. a bacterium producing a large amount of carbon dioxide

D. a fungus that releases a lot of gases during its metabolic activities.

The big holes in swiss cheese are made by a bacterium known as Penicillium shermani which consumes the lactose protein in the cheese to form lactic acid and also releases carbon dioxide(CO₂) and forms a gas bubble which bursts to create big holes in the swiss cheese.