(D) is correct
as option (B) and (C) are eliminated easily because complement surely will contain term (a + b)*ba(a + b)*
[ From B and C, we can get $a^5b$ from (a+b)*ab(a+b)* part, that should not belong to complement of L]
so now to chose between A and D option will eliminate like this :
a*bbbbb* -----> it contain atleast 4 b's so this is correct as compared to (A) option
[From A, we can get $a^5b^3$ from a*bbbb* part, that should not belong to complement of L]