Panama is the closest South American Country to the USA.
Of the three choices, New Zealand is closer to Australia.
Florida is closer to Romania.
Ecuador is the Spanish word meaning Equator. Ecuador has the the Equator running right through it. Panama is just north of Colombia, which is just north of Ecuador so it is the next closest country to the equator. Puerto Rico is Part of the United States but assuming that Puerto Rico is being treated separately, and the actual "Lower 48" US States is what is meant by The US. Puerto Rico is next. Then the US. However this is a trick question! The US has territories closer to the Equator than Puerto Rico, and even closer than the country of Panama. Baker Island at 0°11.7′N has the equator running through its territorial waters!
New Zealand closer to the US.
The equator actually goes through Ecuador so its closer.
Because Laos is closer to the Equator than Romania.
New Zealand is closer to the South Pole than is Australia.
Iceland is closer, BUT New Zealand does claim some Antarctic territory that goes all the way to the South Pole itself.
The UK is the closer.
The Equator runs through Ecuador, a country in South America.
Of course Fiji. New Zealand is just kilometres away from Fiji.