Given that Nu = Nusselt number, Re = Reynoids number, Pr = Prandtl number, Sh = Sherwood number, Sc = Schmidt number and Gr = Grashoff number. The functional relationship for free convective heat transfer is given as,

A

Nu = f(Gr, Pr)

B

Sh = f(Sc, Gr)

C

Nu = f(Re, Pr)

D

Sh = f(Re, Sc)