Given A be a matrix of order \[3\text{ }\times \text{ }4\]
So, \[A\text{ }=\text{ }[{{a}_{i\text{ }j}}]{{~}_{3\times 4}}\]
\[{{R}_{1}}~=\text{ }first\text{ }row\text{ }of\text{ }A\text{ }=\text{ }[{{a}_{11}},\text{ }{{a}_{12}},\text{ }{{a}_{13}},\text{ }{{a}_{14}}]\]
So, order of matrix \[{{R}_{1}}~=\text{ }1\text{ }\times \text{ }4\]
\[{{C}_{2}}~=\text{ }second\text{ }column\text{ }of\]
Therefore order of \[{{C}_{2}}~=\text{ }3\text{ }\times \text{ }1\]