A Ones measured above sea level which is Mount Belinda 1,370 meters above the other one is South Sandwich Trench 8,428 meters below sea level.
B Below sea level because you subtract the above sea level by below sea level you still end up with below sea level.
C 3,529 kilometers below sea level how i did this i subtracted 8,428 by 1,370 and 7,058 than divided that by 2 to get to the center of both