GMAT Critical Reasoning (CR) | Economist: Paying extra for fair-trade coffee—coffee labeled with the

Can someone please explain why A is wrong ?
As per A, if hoarding is a way, then there would not be much impact on the prices of non fair trade coffee and hence the profits of such coffee farmers could remain stable.
As per B, if only 2 out of 100 farmers grow fair trade coffee, and these 2 farmers maintain the large supply of fair trade coffee. I dont find a co-relation between this fact and the impact on profits of non-fair trade coffee farmers.

Many many thanks!

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