A street car moves rectilinearly from station A to the next station B (from rest to rest) with an acceleration varying according to the law `f = a-bx,` where a and b are constants and x is the distance from station A. The distance between the two stations and the maximum velocity are
A. `(2a)/(b)`
B. `(a)/(b)`
C. `(a)/(2b)`
D. `2a - b`