The country can achieve a trade surplus by significantly increasing its exports. Among the given options, increasing exports by $30 billion would transform the current $20 billion trade deficit into a surplus. Therefore, the correct choice is option C. ;
The option that would lead the country to achieve a trade surplus is to increase its exports by $30 billion (option C). This would cover the current $20 billion trade deficit and create an additional surplus of $10 billion. Other options either worsen the deficit or do not eliminate it sufficiently.
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