What are the reference points for longitude and latitude?
the meridian running through Greenwich, England, which is taken as 90° longitude, and the equator, which is taken as 45° latitude
the meridian running through Greenwich, England, which is taken as 0° longitude, and the equator, which is taken as 0° latitude
the north pole which is taken as 90° longitude, and the south pole which is taken as 90° latitude
the equator running through Greenwich, England, which is taken as 0° longitude, and the meridian, which is taken as 0° latitude