Answer:
The correct option is A. Normal microbiota may significantly impact human health and disease.
Step-by-step explanation:
A wide number of microorganisms are present on or inside of our body. All these microorganisms make up the natural microbiota. The normal microbiota is very important to maintain the health of the host.
However, any microbial imbalance can lead to causing disease in its host. The microbiota of the gut have a disease-promoting effect but can also have protective properties. Differences in this microbiota can lead to serious conditions.