The bacterium staphylococcus aureus is commonly found in the nasal cavity of healthy people. if inhaled into the lungs, however, it may cause pneumonia. staphylococcus aureus is best described

1) transient microbiota.
2) a parasite.
3) a mutualist symbiotic partner.
4) resident microbiota.
5) both resident microbiota and opportunistic pathogen.

The correct answer is option 5) "both resident microbiota and opportunistic pathogen".

Explanation:

Resident microbiota are considered all the bacteria that is within the human body of healthy people. Since Staphylococcus aureus is found at the nasal cavity of healthy people is considered part of the resident microbiota. Staphylococcus aureus is also an opportunistic pathogen, because it takes advantage of an unusual opportunity to infect. This opportunity could be to be inhaled into the lungs, or that its host gets immunologically repressed.