Given that s is a String, what does the following loop do?

String r = "";

int i = s.length()-1;

while ( i >= 0 )

{

r += s.charAt(index);

i --;

}

System.out.println( r );

a.) it prints s out backwards

b.) it prints s out backwards but does not print the 0th character

c.) it reverses s and changes it

d.) it generates a new reverse string for s, but keep s with initial information.