Consider the following statement:

String str $=$ new String$("$Learning Java in $21$ days"$)$;

Which of the following statements will print the str string into lowercase, print index of the first a character, and print the length of the str string?

A

System.out.println$($str$.$toLowerCase$)$;

System.out.println$($str$.$indexOf$("$a$"))$;

System.out.println$($str$.$length$0)$;

B

System.out.println$($str$.$LowerCase$))$;

System.out.println$($str$.$indexOf$("$a$"))$;

System out.println$($str$.$length $0$