Harold and Marie went scuba diving. Harold dove to a depth of
 45 feet below sea level. Marie dove to a depth that was 15 feet
 above Harold. Which equation can be used to find Marie's depth,
 in feet?
 A 45-15 = 30
 B (-45) + (-15) = -60
 C (-45) +15=-30
 D 45-(-15) = 60