According to some sports historians, professional tennis players devel

KAPLAN OFFICIAL EXPLANATION:

The author begins by describing the view of some sports historians, who subscribe to a basic formula: physical attributes + a coach's influence = a player's "unique" tennis style. After dismissing the relevance of modern players' greater strength and endurance, however, the author argues that current styles are really no different from previous styles, implying that the historians' claim of the existence of "unique" tennis styles is bogus. And this implication is stated outright in the last sentence, where the author posits the existence of a universally successful tennis style shared by all professionals. In other words, the author uses the fact that tennis styles haven't changed over the years to argue that there's simply one best way to play tennis; in contrast to the historians' theory of "unique," the author proposes the theory of "universality." But the author ignores a plausible alternative explanation; namely, the role of the tennis coach. If, as (D) has it, the early coaches of today's players were the professionals of yesteryear, then it's reasonable to believe that the style the author considers "universal" may simply be the style (one possible one among many) that was handed down from one generation to the next. Perhaps if the current crop of tennis stars don't go on to teach the next generation, whole new styles will develop. If the current style is learned, then it may not be universally inherent to the game. If (D) is true, the author's claim of "universality" is weakened. That makes (D) the winner.

(A) emphasizes the truth of the first part of the sports historians' view regarding the individuality of physical attributes. Since the author doesn't explicitly disagree that players vary in terms of some attributes, this choice doesn't weaken the argument.

(B) if anything, strengthens the argument: If most current players don't know of the players of previous generations, yet their styles are for the most part similar to that of those players, then we'd be more likely to believe that the author is on to something with the claim that a universally efficient style exists in the world of professional tennis.

(C) makes an irrelevant distinction between strength and endurance. Saying that one has a greater impact than the other has no effect on the argument, which never even begins to rank those two factors.

(E) The factors that contribute to the greater strength and weight of today's players are beyond the scope of this argument. The argument focuses on the similarity of styles that is evident once these factors are discounted. Why the current players are stronger and heartier than the previous bunch is not the issue.