Bacteria coat our skin, gut, and mouth. Also present are protists, archaeans, and viruses. Collectively, these organisms are our microbiota. For most members of our microbiota, our body provides their environment, or space, to live. They, in turn, have no effect on us. This is an example of:
A. an antagonistic relationship.
B. mutualism.
C. predation.
D. commensalism.

Explanation:

Commensalism :

1. Is the relationship between two different species in which one species get food or other type of benefits from other species, and in return other,the species is neither benefit nor harmed, it remain unaffected.

2. A commensal species benefits from another species by various ways like obtaining locomotion, shelter, food, or support from the host species, which neither benefits nor is harmed.

3. Example: The remora rides attached to sharks and many other types of fish.

maybe because its impossible for balloons to lift a whole entire house.