Morena, a scuba diver, used the expression below to describe her position in relation to sea level. 0 + (-15) + 6

Which statement could describe the diver’s movements?
A. Morena started at 15 feet below sea level, then dove down 6 more feet.
B. Morena started at 15 feet above sea level, then dove down 6 more feet.
C. Morena started at sea level, dove down 15 feet, then dove down 6 more feet.
D. Morena started at sea level, dove down 15 feet, then rose up 6 feet.