Critical Reasoning

Sportswriter: Many fans have complained loudly about the goaltender when our beloved home team lost important games during the regular season these past five years. Clearly, though, the team's offense has also played a key part in these disappointing losses. Over the past five years, the number of goals scored by the home team has been well below the league average, and further analysis indicates that the average skill level of the team's opponents has remained the same.

Question
The boldface portion of the sportswriter's argument has which of the following functions?

A)It is the main point of the argument.

B)It is evidence that the author attempts to explain.

C)It introduces an opinion the author opposes.

D)It is an opinion that the author ultimately decides is appropriate.

E)It introduces evidence for the author's main point.


[spoiler]The answer choice given is C, "Clearly, though" explains contrast... but is the effect not nullified by " has also played"[/spoiler]