Consider the matrix as given below. $$\begin{bmatrix} 1 & 2 & 3 \\ 0 & 4 & 7 \\ 0 & 0 & 3 \end{bmatrix}$$ Which one of the following options provides the CORRECT values of the eigenvalues of the matrix?

The given matrix is an upper triangular matrix:

For any upper triangular, lower triangular, or diagonal matrix, the eigenvalues are simply the elements on the principal diagonal.

The diagonal elements of matrix $A$ are $1, 4,$ and $3$.

Therefore, the eigenvalues of the matrix are $1, 4, 3$, corresponding to option (A).