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

Mark the tick against the correct answer in the following:

$\left|\begin{array}{lll}b c & b+c & 1 \\ c a & c+a & 1 \\ a b & a+b & 1\end{array}\right|=?$

A. $(a-b)(b-c)(c-a)$

B. $-(a-b)(b-c)(c-a)$

C. $(a+b)(b+c)(c+a)$

D. None of these

Solution: