#### Q 1.

###
Let *G* = (*V* , *E*) be a graph. Define ?(G)=?did×d,whereiG is the number of vertices of degree *d* in *G*. If *S* and *T* are two different trees with ? (*S* ) = ? (*T*), then

*G*= (

*V*,

*E*) be a graph. Define

*d*in

*G*. If

*S*and

*T*are two different trees with ? (

*S*) = ? (

*T*), then

(A) | (B) | (C) | (D) |