Which one of the following examples of use of therefore best reflects its meaning?单项选择题

The university offered him a hefty scholarship. Therefore, he accepted it immediately.

The paper was given a negative review by the anonymous reviewers. Therefore, it must have been badly written.

Findings from a number of sources suggest that teenage boys have a much higher tendency to smoke than teenage girls. Therefore, the health ministry’s efforts to prevent smoking among teenagers should target primarily at boys.

The methodology is problematic because the sample size is small but not sufficiently representative. Therefore, the researchers should use a larger, more representative size for their data collection, so that the findings can be more convincing.