Derrick can row a boat at a speed of miles per hour in still water. On Sunday, he went boating in a river with a current of miles per hour. He rows miles with the current, and then mile against the current, taking a total of hours. Which equation could be used to represent this situation? A 15 z−35−z=214 5 z 1 ​ − 5−z 3 ​ =2 4 1 ​ B 35 z 15−z=214 5 z 3 ​ 5−z 1 ​ =2 4 1 ​ C 5 z3−5−z1=214 3 5 z ​ − 1 5−z ​ =2 4 1 ​ D 13(5 z) 11(5−z)=214 3(5 z) 1 ​ 1(5−z) 1 ​ =2 4 1 ​