Answer
a.
Work Step by Step
The pressure would still level off, although this could occur at a dangerous point. After all, even at high pressures, there will still be an equilibrium where water goes between being in the liquid phase to being in the gas phase at the same rate. Thus, the pressure would level off. (However, since this leveling off can occur at a dangerously high pressure, it is still vital to check your pressure cooker's regulating mechanism before use.)
