The peak magnitude of a flood hydrograph during 4-hr study duration over a catchment is 300 m3 / s. The total depth of rainfall is 6 cm; and the infiltration loss during the said 4-hr period is 2 cm. A constant uniform base flow of 20 m3 / s is premised throughout. The peak value of the corresponding 4-hr unit hydrograph is

• A. 75 m3 / s
• B. 70 m3 / s
• C. 50 m3 / s
• D. 40 m3 / s