Q. The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be

• (A) W/m.k
• (B) W/m
• (C) W/m.k2
• (D) None, 'a' is just a number