Let $\omega$ be a complex cube root of unity with $\omega\neq 1$ and $p=[P_{ij}]$ be a $n\times n$ matrix with $P_{ij}=\omega^{i+j}$.Then $P^2\neq 0$ when $n$=

Question

$(a)\;57\qquad(b)\;58\qquad(c)\;60\qquad(d)\;61$