iongmat wrote:I am also having a tough time digesting that enzymes are attempt. I mean..enzymes and attempt do not seem to be logical comparisons; production and attempt do seem more logical.

i don't disagree with what you're saying here, but ... that's not an option. so there's not much of a point in worrying about it.
the only decision you have to make here is between "attempt" and "trying", and, between those two, "attempt" is the winner.

remember, you're not trying to formulate an "ideal" sentence; your only job is to pick the best answer choice.

it's easy to lose sight of this fact and to start trying to "edit" GMAC's sentences. (i'm a professional editor myself, among other things, so this temptation is perhaps even stronger for me.) however, if you want to be as prepared as possible for the test you're actually going to take, it's important not to let yourself get sidetracked.