Associate law of vector addition is

The correct option is A The sum of vectors remains same irrespective of their order or grouping in which they are arranged.
Associative Property of Vector addition - For any three vectors $\overline{a}$, $\overline{b}$ and $\overline{c}$, $\Rightarrow (\overline{a}+\overline{b})+\overline{c}=\overline{a}+(\overline{b}+\overline{c})$