The bacterial species staphylococus aureus is found on the skin and in the nasal passages of about 20% of the human population. in healthy individuals, s. aureus is benign (does not cause harm) in these locations. however, if it is introduced into the bloodstream through, for example, a wound, it can make a person gravely ill. thus, the ecological relationship of s. aureus with a human:
a. is always mutualistic.
b. is always antagonistic.
c. can be mutualistic or antagonistic.
d. is fixed or unchanging.
e. is benign.