\textbf{155.} The number of Latin squares compatible with the Latin square
$\begin{pmatrix} 3 & 1 & 2 \\ 1 & 2 & 3 \\ 2 & 3 & 1 \end{pmatrix}$
is which of the following?
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(1) $2$ \hfill (2) $3$ \hfill (3) $4$ \hfill (4) $6$
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