Jerry bought a pizza of diameter of 12". A sector of the pizza was cut which had a surface area of $4.5 \pi$. The angle of the cut sector was

Question

$\begin{array}{1 1} (a)\; 30^{\circ} \\ (b)\; 45^{\circ} \\ (c)\; 60^{\circ} \\ (d)\; 75^{\circ} \end{array}$