The Following Method Recognizes Whether a String Parameter Consists of a Specific

The following method recognizes whether a String parameter consists of a specific pattern and returns True if the String has that pattern, false otherwise. Use this recursive method to answer the questions below.
public boolean patternRecognizer(String a)
{
if (a == null) return false;
else if (a.length( ) = = 1 | | (a.length( ) = = 2 && a.charAt(0) = = a.charAt(1) ) ) return True;
else if (a.length( ) = = 2 && a.charAt(0) != a.charAt(1) ) return false;
else if (a.charAt(0) == a.charAt(a.length( ) - 1) )
return patternRecognizer(a.substring(1, a.length( ) - 1) ) ;
else return false;
}
-If the method is called as patternRecognizer(x) where x is "aa", what will the result be?

A) True
B) false
C) a NullPointerException
D) a run-time error
E) infinite recursion