A thermodynamic cycle xyzx is shown on a V-T diagram.

The P-V diagram that best describes this cycle is: (Diagrams are schematic and not to scale)

For process $$x \to y$$:  $$V \propto T \implies P = \text{constant (Isobaric)}$$

$$\text{Volume increases, so it's a horizontal line pointing right.}$$

For process $$y \to z$$: $$V = \text{constant (Isochoric)}$$

$$\text{Temperature decreases } \implies P \text{ decreases, so it's a vertical line pointing down.}$$

For process $$z \to x$$:  $$T = \text{constant (Isothermal)}$$

$$\text{Volume decreases } \implies P \propto \frac{1}{V} \text{ increases, so it's a hyperbolic curve rising up.}$$