A scuba diver descends farther down into the ocean from an initial depth of 12.8 feet below sea level. The scuba diver descends at a constant rate for 312 minutes and reaches a depth no more than 49.2 feet below sea level. What is the maximum rate, r, that the scuba diver may descend?

r≥10.4

r≤10.4

r≥13 7/9

r≤13 7/9