A geologist digs 5 feet down into the ground before taking a break. This process is repeated 3 times to create a hole that has a total depth of 15 feet.
Which equation represents the hole's depth in relation to ground level?
A. -5 • 3 = -15
B. -3 • -5 = -15
C. -3 • 5 = 15
D. 5 • 3 = 15
•= multiplication