The microorganisms that make up the normal human flora are important for which of the following?

The correct answer to this question would be:

The microorganisms that make up the normal human flora are important for “preventing the colonization and multiplication of pathogens”.

The human flora or human microbiota is the totality of microorganisms which resides on or within our body. The normal flora of humans is composed of a few eukaryotic fungi and protists, but bacteria are the most abundant and obvious microbial components of the normal flora. The microorganisms of the normal flora help the body fights against the pathogens by challenging for microenvironments more effectively than such pathogens or by supplying nutrients the body can use.