Suppose that alphabet $=\{a,b\},$

and, for any string that win${}^{**},$ let $n_a(w)$ denote the number of $a\text{'}$s in string

$w.$

Which of the following is a deterministic finite accepter $($dfa$)$ such that the

language accepted by that dfa is $\{\begin{array}{cc}\text{w}\text{i}\text{n}& {}^{**}\text{:}{n}_a(w)\end{array}$ is even