The given graph represents the variations of compressibility factor `Z=PV//nRT` vs `P` for three real gases `A`, `B`, and `C`.
Identify the incorrect statements.
A. For the gas `A,a=0` and its dependence on `p` is linear at all pressure
B. For the gas `B,b=0` and its dependence on `p` is linear at all pressure
C. For the gas `C` which is typical real gas for which neither `a` nor `b=0`. By knowing the minima and the point of intersection, with `Z=1,a` and `b` can be calculated
D. At high pressure, the slope is positive for all real gases
