Which of the following regular expression allows strings on {a,b}* with length n where n is a multiple of 4.a) (a+b+ab+ba+aa+bb+aba+bab+abab+baba)*b) (bbbb+aaa

• A. (a+b+ab+ba+aa+bb+aba+bab+abab+baba)*b) (bbbb+aaaa)*c) ((a+b)(a+b)(a+b)(a+
• B. (bbbb+aaaa)*
• C. ((a+b)(a+b)(a+b)(a+b))*
• D. None of the mentioned