For what values of x and y, matrix \( A = \begin{bmatrix} 1 & 1 & 1 \\ 4 & x & 4 \\ 0 & y & 5 \end{bmatrix} \) will be singular (inverse does not exist):

A \( x = 4 \) and \( y = 3 \)

B \( x = 4 \) and \( y = 4 \)

C \( x = 4 \) and \( y = 5 \)