Answer:
<em>1. Modern players are much more muscular—it’s rare to see a lanky player anymore—than are players from the past.</em>
Explanation:
Some of the situations in which we use dashes in a sentence is to make a statement, a remark, or a comment that add information to a part of a sentence or to clarify such part, although they are not necessary to the meaning of the full sentence, which means that if the words set off by dashes are taken out, the sentence would still make perfect sense. Very often, they are used for emphasis, and they interrupt a sentence to a certain point.
Thus, sentence number 1 is the correct answer because the dashes are put to add a comment about a previous statement "Modern players are much more muscular". Furthermore, the dashes are also placed in the right places, because if we were to take out what it is set off by the dashes, the sentence would still make perfect sense, and this does not happen with the other given options.