What is the volumetric strain in the thin cylinder subjected to internal pressure having hoop stress of 200 MPa, modulus of elasticity, E = 200 GPa and poissons ratio = 0.25?

A

$$\frac{20}{1000}$$

B

$$\frac{2}{1000}$$

C

$$\frac{0.2}{1000}$$

D

$$\frac{0.02}{1000}$$