In Case A, water flows through an 8-inch schedule 40 pipe with a discharge of 75 liters per second. In Case B, the schedule is changed to 80. The mean velocity is the same in both cases. Calculate the discharge in units of L/s for case B. Choose the closest answer (L/s): 

(a) 68,

(b) 74, 

(c) 75, 

(d) 79, 

(e) 82.