The defining characteristics of a public policy are that it must affect many people, be accepted as legitimate, and:

Public policy is the way a legislature keeps up order or addresses the requirements of its nationals and can be found for various segments, for example, health and law & order. Public policy is continually changing as the requirements of a general public change. These can be changed by residents through verbal confrontations and votes.

the correct answer is modern american cars are not available due to trade restrictions.

trade between cuba and the united states have serious restrictions. the u.s. imposed an economic embargo on cuba, that among other things means that modern american cars are not available due to trade restrictions.

in response to some governmental actions of the authorities from cuba, president john f. kennedy proclaimed an embargo on trade between both countries in february 1962. the trade embargo remains active until this day and was implemented directly by the departments of commerce and the department of treasury.

in president trump’s administration, there is a national security presidential memorandum that "strengthens the policy of the u. s.", affecting trade with cuba.