Consider the following incomplete code segment, which is intended to increase the value of each digit in a String by one. For example, if num is 12345, then the resulting String would be 23456.

String num = "12345";
int counter = 0;
String result = "";
while(/* Missing Loop Header */)
{
int newNum = Integer.valueOf(num.substring(counter,counter+1));
result+= (newNum + 1);
counter++;
}
System.out.println(result);

Which of the following should replace /* Missing Loop Header */ so that the code segment works as intended?

counter < num.length() - 1


counter <= num.length()


counter < num.length()


counter > num.length()


counter < num.indexOf(counter)