The ordinate of a 4-hour unit hydrograph at 2 hour time intervals starting from time t = 0 are as follows : 0, 20, 80, 128, 152, 135, 88, 55, 24, 7, 1 and 0 m³/s. The peak of 2-hour unit hydrograph would be_______m³/s,
A. 168
B. 48
C. 84
D. 345