Environmental organizations want to preserve the land surrounding the

Let's break down the argument and see what role each sentence plays.

Environmentalist's goal/aim - preserve the land surrounding the WWA from residential development
Environmentalist's strategy/plan - purchasing that land from the farmers who own it.
Author's opinion on their plan - That plan is ill-conceived
Reason why his opinion is so - if the farmers did sell their land, they would sell it to the highest bidder, and developers would outbid any other bidders.

Author's strategy/plan for that goal - Assist the farmers to modernize their farms to the extent needed to maintain viability
Reasons he thinks this is a good strategy - Farmers will never actually sell any of the land, provided that farming it remains viable. But farming will not remain viable if the farms are left unmodernized, and most of the farmers lack the financial resources modernization requires.

(A) The first assesses the goal held by certain environmental organization; the second presents the logical goal that the reasoning concludes should be adopted instead.

The author does not assess the "goal" of the environmentalists. He doesn't say whether "preserving the land" is a good idea or not. He assesses their plan. He says that purchasing that land from the farmers is not a good strategy.


(B) The first assesses the goal held by certain environmental organization; the second presents the strategy that the reasoning concludes has the best chance of reaching that goal.

Same logic as above.

(C) The first is the conclusion reached about one strategy for attaining a certain goal; the second presents the strategy that the reasoning advocates.

Correct. The first is the author's conclusion about the environmentalist's strategy (that the plan is not good). The second is the strategy that the author supports.

(D) The first is the main conclusion toward which the reasoning is directed; the second presents a strategy that is called sensible but for which no support is offered.

We could say that the first is the main conclusion but it is only a part of the main conclusion.
The main conclusion would be - The plan of the environmentalists is not good. A better plan is to help modernise.

The second does present a strategy but support has been provided for it. So this option is incorrect.

(E) The first is the main conclusion toward which the reasoning is directed; the second is a consideration raised in order to support that conclusion

Again, the first is a part of the main conclusion of the argument but the second is not supporting that conclusion. What supports that the plan is ill-conceived is this: "if the farmers did sell their land, they would sell it to the highest bidder, and developers would outbid any other bidders."
The second boldface statement gives an alternative strategy.

Answer (C)