# The characteristic root of the matrix $\begin{bmatrix}1&0&0\\2&3&0\\4&5&6\end{bmatrix}$ are

$(a)\;1,3,6\qquad(b)\;1,2,4\qquad(c)\;4,5,6\qquad(d)\;2,4,6$

Since the given matrix is a triangular matrix so its characteristic roots are the diagonal elements.Hence the required roots are 1,3,6
Hence (a) is the correct answer.