Which of the following statements about the Freundlich isotherm $x/m=k{p}^{1/n}$ for a gas are correct?

1. AA plot of $\log (x/m)$ against $\log p$ is a straight line
2. BThe value of $1/n$ lies between $0$ and $1$ in the usual range
3. C$x/m$ increases linearly with $p$ at all pressures
4. DIt fails at sufficiently high pressure