If $\Delta=\begin{vmatrix}x^n&x^{n+2}&x^{2n}\\1&x^p&p\\x^{n+5}&x^{p+6}&x^{2n+5}\end{vmatrix}=0$ then $p$ is given by

Question

$(a)\;x^n\qquad(b)\;(n+1)\qquad(c)\;either\;(a)\;or\;(b)\qquad(d)\;both\;(a)\;and\;(b)$