Question

which tool might be used to limit imports from cuba but maintain exports to cuba?
restricted trade routes
embargo
nafta
sanctions

Explanation:

An embargo is a complete ban on trade with a particular country. If a country wants to limit imports from Cuba but maintain exports to Cuba, an embargo is not the right choice as it stops all trade. NAFTA (North American Free Trade Agreement) was a trade agreement between the US, Canada, and Mexico and not relevant here. Restricted trade routes are not a standard trade - limiting tool in the context of country - level trade restrictions. Sanctions can be targeted. For example, a country can impose import sanctions on Cuba (limit imports) while still allowing its own companies to export to Cuba.

Answer:

sanctions