A ten-year comparison between the United States and the Soviet Union in terms of crop yields per acre revealed that when only planted acreage is compared, Soviet yields were equal to 68 percent of United States yields. When total agricultural acreage (planted acreage plus fallow acreage) is compared, however, Soviet yield was 114 percent of United States yield.

From the information above, which of the following can be most reliably inferred about United States and Soviet agriculture during the ten-year period?

A A higher percentage of total agricultural acreage was fallow in the United States than in the Soviet Union.
B The United States had more fallow acreage than planted acreage.
C Fewer total acres of available agricultural land were fallow in the Soviet Union than in the United States.
D The Soviet Union had more planted acreage than fallow acreage.
E The Soviet Union produced a greater volume of crops than the United States produced.
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The key is to understand that we are asked about "crop yields per acre".

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Fallow = 0 Yield.

Let R and US have the same agricultural land, say 100x.
US has yield of 1, Russia of 0.68.
So Us produces 100 units and Russia 68 Units.

Adding the fallow area that has yield = 0, we are told that Russia's total yield is now bigger than that of the US.
Russia's ratio --> production / (planted+fallow) is bigger than the US'.
The only way this can happen is if the US fallow land increases by a larger absolute amount than Russia's.

In other terms, the yield is more diluted in the US than in Russia, because the overall agricultural land comprises more fallow area.