This presents another potential explanation for the drop in average number of visits per representative. If the number of representatives increased, so that representatives could spend more time on each physician, we’d expect average number of visits per rep to go down.

Whether physicians accept free samples doesn’t affect how we interpret the drop in average number of visits per representative.

This concerns direct advertising to consumers, which has no clear impact on advertising in the form of sending representatives to physicians.

This concerns the number of times a physician will see the same representative. This has no clear impact on how we interpret a statistic about how many overall visits an individual representative makes per year.

This suggests that visits to a physician can be effective, if they occur. But the author’s position is that there were fewer visits this year. So, (E) is consistent with the author’s position.