单项选择题

一均匀稳态河段,河宽100m,平均水深2m,流速0.5m/s,平均底坡i=0.0005。一个拟建项目以岸边和河中心两种方案排放污水的完全混合距离为()

A.26374.7m,6593.7m
B.6593.7m,26374.7m
C.7903.6m,17394.7m
D.17394.7m,7903.6m