Which statement best describes a country with a diversified economy? country c has ten percent farmable land and uses all of it to produce corn. country d has crude oil reserves and also exports gold and grain. country b has wheat crops that make up 90 percent of its trade exports. country a imports more goods and services than it exports.

I think the correct answer would be the second option. The statement that would describe a country with a diversified economy would be country D that has crude oil reserves and also exports gold and grain.  This type of economy involves a number of varying streams of revenue and providing the nations the ability to sustain growth due to not relying only to one source of revenue. This type of economy provides the reliability and security that a country would need in case one source of revenue would fail. 

Depends on your opinion but i agree