Could be false. To say that these clinical trials are never conducted by a sole physician is too extreme. We know that these trials are usually conducted by multiple physicians, but this does not mean that all of them are.

Must be true. We know that most of these reports have multiple authors because the stimulus tells us that **usually** these reports are coauthored by physicians from each participating hospital.

Could be false. The information in the stimulus is restricted to certain clinical trials and physics papers. We don't know about all technical articles.

Could be false. This answer choice reverses a relationship in the stimulus. The stimulus tells us that usually physics papers about experiments using subsystems developed at each laboratory have authors from each laboratory. This does not imply that physics papers that are authored by multiple researchers usually report results related to subsystems. (The fact that X is usually Y does not imply that Y is usually X.)

Could be false. The information in the stimulus is restricted to certain clinical trials and physics papers. We don't know about most technical articles.