You have reports from four different studies of the effects of a new pesticide
on native populations of bees. Each report makes different claims about
whether the pesticide will harm bees and how harming bees can be avoided,
but the studies were done differently. Which of these studies would produce
the most trustworthy results?
A. An investigation whose results have been replicated by several
independent research teams.
B. A preliminary study conducted for the company that makes the
pesticide.
C. A summary of the observations made by the farmers who field-
tested the new pesticide.
D. A non-replicated experiment conducted by a company that
competes with the pesticide maker.