Analyze the following code:

import java.util.$*$;

public class Test

public static void nain $($String$[]$ args$)$ throws Exception $\{$

TreeSet set $=$ new TreeSet$<>()$ :

set. add $("$Red$")$ :

set.add $("$Green$")$ :

set $.$add $("$Blue$")$ :

System.out println$($set$.$last $())$ :

Time left

$*$ a$.$ The program displays Blue.

$*$ b$.$ The program may display Red, Blue, or Green.

$*$ c$.$ The program cannot compile, because the last method is not defined in Set.

$*$ d$.$ The program displays Red.

$*$ e$.$ The program displays Green.