下列程序段的执行结果为______。S= 0: T= 0: U=0For X = 1 To 3 For Y = 1 To X For Z = Y To 3 S= S +1 Next Z T=T+1 Next Y U=U+1Next XPrint S; T;U

A．3 6 14

B．14 6 3

C．14 3 6

D．16 4 3