$\begin {array} {1 1} (A)\;Free\: electrons\: do\: not\: move \\ (B)\;The\: average\: speed \: of\: a \: free\: electron\: over\: a\: large \: interval \: of\: time \: is \: zero \\ (C)\;The\: average\: velocity \: of\: a\: free\: electron\: over\: a\: very\: small\: interval\: of\: time\: is \: zero \\ (D)\;The\: average\: of\: the\: velocities\: of\: all\: free\: electrons\: at\: any\: instant\: is \: zero \end {array}$
