Column Matrix

Q. If $A=\left[\begin{array}{ccc}0& 1& 2\\ 1& 2& 3\\ 3& a& 1\end{array}\right]$ and $A^{-1}=\left[\begin{array}{ccc}1/2& 1/2& 1/2\\ -4& 3& c\\ 5/2& -3/2& 1/2\end{array}\right]$ then the values of $a$ and $c$ are equal to

1. 1, 1
2. 1, 2
3. 1.-1
4. -1, 1

Q.

The order of a column matrix can be

1. 2 x 2

2. 1 x 2

3. 3 x 1

4. 3 x 2