A committee consists of six members (A, B, C, D, E, and F). A has veto power, B, C, D, and E each have one vote. F is a nonvoting member. For a motion to pass it must have the support of A plus at least two additional voting members.
What is the Banzhaf power index of player A?
\begin{itemize}
\item A. $\frac{1}{3}$
\item B. $\frac{7}{11}$
\item C. $\frac{5}{11}$
\item D. $\frac{11}{23}$
\item E. none of these
\end{itemize}