(B) This cannot be determined without knowing the orientation of the rod relative to the magnetic field.
Because, Since acceleration of the rod is Zero. So, net force acting on the rod will be zero. But, its not specified that whether the rod is moving along varying magnetic field direction or a constant magnetic field direction.
There is only one pressure this situation would be a "constant pressure" process. The work done by expanding gas is. =p(delta V) = (1.5e3)(5.e3)(5.4e-5) N/m^2xm^3) N/m2xm^3= 8.1e-2 N-m ANS