pressure developed in the cube

Question

A steel cube, with all faces to deform, has Young’s modulus, E, Poisson’s ratio, $\nu$, and coefficient
of thermal expansion, $\alpha$. The pressure (hydrostatic stress) developed within the cube, when it is
subjected to a uniform increase in temperature, $\Delta T$, is given by

 

(a) 0                                  (b)$\frac{\alpha (\Delta T)E}{1-2\nu }$
(c) $-\frac{\alpha (\Delta T)E}{1-2\nu }$                  (d)$\frac{\alpha (\Delta T)E}{3(1-2\nu) }$