During uniaxial compressive testing of a rock specimen of diameter 54 mm and length 120 mm, the axial strain was found to be 6.5 × 10^-4 mm/mm. If the Poisson's ratio of the rock is 0.3, the volumetric strain of the rock specimen in mm/mm is

A. 1.95 ∗ 10^-4

B. 2.60 ∗ 10^-4

C. 2.34 ∗ 0^-2

D. 3.12 ∗ 10^-2

Answer: Option B