Steady two-dimensional heat conduction takes place in the body shown in the fig below. The normal temperature gradients over surface P and Q can be considered to be uniform. The temperature gradient ∂T/∂x= at surface Q is equal to 10 K/m. surfaces P and Q are maintained at constant temperatures as shown in fig. While the remaining part of the boundary is insulated. The body has a constant thermal conductivity of 0.1 W/mk, the value of ∂T/∂x and ∂T/∂y at surface P are

A. ∂T/∂x=20 K/m, ∂T/∂y=0 K/m B. ∂T/∂x=0 K/m, ∂T/∂y=10 K/m C. ∂T/∂x=10 K/m, ∂T/∂y=10 K/m D. ∂T/∂x=0 K/m, ∂T/∂y=20 K/m