i received a private message about this thread.

mitch wrote:

GMATGuruNY wrote:My recommendation: when you see THIS X in an SC, ask yourself whether it's clear what THIS X refers to.
If the referent is CLEAR -- if you know that this predator serves to describe the wolves of Minnesota -- don't eliminate the answer choice.
If the referent is UNCLEAR -- if you can't figure out who this sportsperson is -- eliminate the answer choice.

this is pretty much a perfect summary; i have very little to add to it.

the only additional consideration i might add here is that you should be familiar with the use of singular nouns to represent the collective of all such nouns worldwide -- especially nouns that represent animals, objects (particularly those with some sort of social significance), or social phenomena.
The right whale is endangered worldwide. --> clearly, we are not talking about just one whale; we are talking about all of them.
The footrace is perhaps the most universal form of human competition. --> this does not mean that the entire human race competes in a single footrace.
The skirt is a symbol of femininity in North America, but not everywhere.
etc.