The Prime Meridian passes through which place?

The correct answer is B, Greenwich, the site of the old Royal Observatory near London. The meridian running through it was accepted as the zero meridian, from which all longitudes are counted east and west, and its local time is Greenwich Mean Time, the reference for the world's standard times.

Option A, Paris, is a strong distractor because France long used its own prime meridian through the Paris Observatory before the international agreement. Option C, Rome, and option D, Washington, were never adopted as the zero meridian, although several countries did use national meridians of their own in the nineteenth century. Remember the pair of extremes for this chapter: the equator is the reference for latitude and the Greenwich meridian is the reference for longitude, and the meridian directly opposite Greenwich, at 180 degrees, is the one the International Date Line broadly follows.