Mark the tick against the correct answer in the following:
Question:

Mark the tick against the correct answer in the following:

$\left|\begin{array}{ccc}1 & 1+p & 1+p+q \\ 2 & 3+2 p & 1+3 p+2 q \\ 3 & 6+3 p & 1+6 p+3 q\end{array}\right|=?$

A. 0

B. 1

C. $-1$

D. none of these

Solution: