Which of the following, if true, would most weaken the author's theory that the bad state of the Grauballe man's teeth suggested that he had not lived exclusively on the type of vegetable diet that his last meal represented?
Incorrect.
[[snippet]]This answer choice supports, not weakens, the author's theory. If eating meat makes teeth deteriorate, then it strengthens the author's conclusion that a diet not based on vegetables caused the poor state of the Grauballe mans' teeth.
Incorrect.
[[snippet]]While this answer choice may be seen as reducing the chances that the author's theory is correct, thereby weakening it, notice that the author draws a conclusion about the Grauballe man alone, who may or may not have had a vegetarian diet, regardless of the times.
At any rate, there is an answer choice which more significantly weakens the author's conclusion. Look for it!
Incorrect.
[[snippet]]This answer choice strengthens rather than weakens the author's theory, by ruling out an alternative explanation - that the Grauballe man's last meal had something to do with the state of his teeth.
Incorrect.
[[snippet]]This answer choice neither weakens nor strengthens the author's theory. Even if the Grauballe man's diet was detrimental to his teeth, it still may have been beneficial for his bones.
Good!
[[snippet]]This answer choice attacks the assumption that the man's teeth were in a bad state because of the food he usually ate by giving an alternative explanation for their bad condition.