According to robert merton, what is the importance of using the conceptual scheme of
latent functions (unforeseen or unintended consequences) and manifest functions
(purposed consequences)?

Robert Merton (1910 – 2003) have made an extensive contribution to the theory of Structural functionalism. In particular, by sharpening the concepts of latent and manifest functions and applying them to sociology.

Merton was arguing that while studying a certain social phenomenon, it is important to identify both manifest and latent functions of this phenomenon.  

For example, looking at festivals, they appear to have manifest functions of cultural development and social bonding. Meanwhile, they also have latent function of excessive garbage production and traffic jams.  

the united states has a federal government. the president is the head of the federal government of the united states. however, each state forms its government for administration purposes. the powers of the state governments are exercised within restricted state boundaries. and citizens participate in this government by voting.

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.