\begin{table}%t4
%\centering
\par
\caption {\label{tab_max_zc}Redshift of the cluster which maximizes the number of objects
  detected at $z=8$ for the three LF respectively {\it from top to bottom} {\bf a)}, 
  {\bf b)}
  and {\bf c)}.} 
\par
\begin{tabular}{cc c c} 
\hline\hline
\noalign{\smallskip}
LF & A1689 & A1835 & AC114 \\
\hline
actual $z_{\rm c}$ & 0.184 & 0.253 & 0.310 \\
(a) & 0.10 & 0.05 & 0.25 \\
(b) & 0.15 & 0.10 & 0.25 \\
(c) & 0.20 & 0.10 & 0.30 \\
\hline
\end{tabular}
\end{table}