The correct option is B heterotrophic bacteria
Heterotrophs are a group of microorganisms that use organic carbon as food, as opposed to autotrophs like algae that use sunlight.
Lactic acid bacteria (LAB) such as Lactobacillus, are helpful in making curd from milk.
Antibiotic drugs are obtained from living organisms such as fungi, molds, and certain soil bacteria that are harmful to disease-causing bacteria.