Which statement is true?

time zones are exactly 15° apart around earth.

time zone borders on land may curve to keep regions together.

there are 12 time zones around earth.

each country or nation has only one time zone.

The first one

Explanation:

Each time zone is 15° apart longitude wide the distance between the zones,

greatest at the equator and shrinks to zero at the poles, due to the curvature of Earth.

the correct answers are:

a - pacific plate;

it is the biggest oceanic tectonic plate. surrounded on all sides by continental tectonic plates, it is submerging and gradually becoming smaller and smaller.

b - north american plate;

huge continental plate, occupying big portion of the northern hemisphere.

c -eurasian plate;

alongside the north american plate, it is one of the two dominant continental plates in the northern hemisphere.

d - indian plate;

a small continental plate, that has been part of gondwanaland initially, but after the break up of it, moved towards northeast and pushed into the eurasian plate that was once part of laurasia.