Read this passage: killer bees are not just "regular" bees. regular bees (which are called european honeybees) pose health threats, for sure, to people who are already allergic to them. have you seen those epipens that some people have to carry around because they are super allergic, even to regular bees? i know.

which phrase in this passage from "the killers in our midst" gives it a casual style?

a. regular bees
b. some people
c. for sure
d. killer bees