Question

separating the northern and southern hemisphere, this line is at 0 degrees latitude.
tropic of cancer
equator
tropic of capricorn
prime meridian

Explanation:

The equator is the line at 0 - degree latitude that separates the Northern and Southern Hemispheres. The Tropic of Cancer is at 23.5°N, the Tropic of Capricorn is at 23.5°S, and the Prime Meridian is at 0 - degree longitude.

Answer:

B. Equator