The set of strings over $\{a,b,c\}$ that begin with a$,$ contain exactly two b$\text{'}$s$,$ and

end with cc$.$

$a(abc{)}^{*}bb(abc{)}^{*}cc$

$a(ac{)}^{*}bb(ac{)}^{*}cc$

Prefer not to answer

$a(ac{)}^{*}b(ac{)}^{*}b(ac{)}^{*}cc$

$ab(abc{)}^{*}bcc$