The length of the shortest string NOT in the language (over = {a, b}) of the following regular expression is _____________a*b*(ba)*a*

The length of the shortest string NOT in the language (over = {a, b}

1.	The length of the shortest string NOT in the language (over = {a, b}) of the following regular expression is _____________ ab(ba)a
A.	2
B.	3
C.	4
D.	5
Answer» C. 4