For 1 mol of gas, the plot of pV vs p is shown below. p is the pressure and V is the volume of the gas.

What is the value of compressibility factor at point A?

A

$$1 - \frac{a}{RTV}$$

B

$$1 + \frac{b}{V}$$

C

$$1 - \frac{b}{V}$$

D

$$1 + \frac{a}{RTV}$$