The correct answer is option 4, the Equator. The Equator is an imaginary line that divides the Earth into the Northern Hemisphere and the Southern Hemisphere. When it is the vernal or autumnal equinox (around March 20th and September 22nd) the tilt of the Earth`s axis causes the Sun to be directly over the Equator. This means that the length of day and night is approximately equal everywhere on Earth. During this time, there are 12 hours of daylight and 12 hours of darkness at the Equator. In contrast, the North and South Poles experience six months of continuous daylight and six months of continuous darkness, while the Prime Meridian and Antarctic do not have equal day and night lengths. Therefore, the correct answer is the Equator.