During the 1968 Pueblo incidentAnswer Choices: A) U.S. soldiers were caught smuggling guns and butter into North Vietnam. B) Mexican Americans...

The only one of these answers that is anywhere near to
being correct is D.   The USS Pueblo was an American spy ship that was captured by the
North Korean navy.

The Pueblo was on a mission to collect
electronic intelligence about North Korea.  This is intelligence about North Korean
radar, radio transmissions, and things like that.  While the Pueblo was doing that, the
North Koreans boarded and captured it.

This was an
embarassing incident for the US.  The sailors were held by the North Koreans for almost
a year.  North Korea used them and the incident for propaganda purposes.  The US had to
apologize and promise to stop spying before North Korea returned the sailors (though the
US retracted the apology and the promise after they were
released).