How is the equator similar to the prime meridian?

Answer 1

Both divide the earth between north and south or east and west.

Answer 2

They are great circles with circumferences equal to the
circumference of the planet.
The prime meridian is zero longitude
originally chosen to start counting east and west from Greenwich England.
The equator is zero latitude and latitude is measured north and south from the equator.

Answer 3

(I took the quiz as well so this answer is the right one)
Both the equator and the prime meridian are imaginary base lines from which locations of the earth can be measured.