If r = 0, 1, 2, ........10, let Ar, Br and Cr denote, respectively, the coefficent of xr in the expansions of (1 + x)10, (1 + x)20 and (1 + x)30. Then \(\sum\limits_{r=1}^{10}\) Ar (B10Br – C10Ar) is equal to
(a) B10 – C10
(b) A10 (B102 – C10A10)
(c) 0
(d) C10 – B10