The determinant of the matrix $$\begin{bmatrix}2 &0 &0 &0 \\ 8& 1& 7& 2\\ 2& 0&2 &0 \\ 9&0 & 6 & 1 \end{bmatrix}$$
Answer: A
I reduced it to an upper triangular matrix.
2*1*2*1 = 4 so option A is right
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