If $X= \{ 4^n-3n-1:n \in N\}$ and $Y=\{9(n-1):n \in N\}$. Where $N$ is the set of natural numbers , then $X \cup Y$ is equal to

Question

$\begin{array}{1 1}(A)\;N \\ (B)\;Y-X \\(C)\;X \\(D)\;Y \end{array}$