1 Prior to entering WWI, the U. S. protested Germany's use of un-restricted submarine warfare mainly because it O (1) violated the Monroe Doctrine O (2) discouraged immigration to the U. S. 0 ( (3) posed a direct threat to American cities 0 (4) violated the principle of freedom of the seas

Violated the principle of freedom of the seas​

Explanation:

A German U-boat had sunk the British passenger ship the Lusitania at great loss of life. ... This eventually led to the American declaration of war on Germany.

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.

protectionism fosters competition and keeps price regulated is not an argument in favor of protectionism.