$(20$ points$)$ Use the pumping lemma for context free languages to show that each of the following languages are not

context free. Be very explicit in your argument$-$ missing steps will be assumed incorrect.

$($a$)A=\{\begin{array}{ccc}{0}^{n}w\text{:}\text{w}\text{i}\text{n}& \{0,& 1{\}}^{**}\end{array}$ contains $n$ zeros and $n$ ones