Read the following selection from the section "Device Could Deliver Drugs."
Despite our many medical advances, we’re pretty bad at measuring core body temperature. A recent study of 8,600 patients found that thermometer readings from the mouth, armpit or skin did a lousy job of measuring core temperature.
What kind of a tone does the author create by using the phrases "we're pretty bad" and "lousy job"?
(A) frightened
(B) informal
(C) objective
(D) serious