Some Confusing in behavior of Widening, Autoboxing VarArgs method Choice made

Question

I'm bit confusing in the way overloading works with widnening, Autoboxing, and Varargs, I tried to understand the concept as much as i can but there is still some cases I can't get the way of generating the output of them.

I need to understand the output of the follow example

public static void main(String[] args){
   int[] x = new int[3];
   Integer[] y = new Integer[5];

   doStuff(x);
   doStuff(y);
   doStuff(null);
}

static void doStuff(Object... x){
    System.out.println("Object...");
}

static void doStuff(Object x){
    System.out.println("Object");
}

The output is :

Object
Object...
Object...

Can anyone help me understanding how this output is generated? I tried to search and read a lot using google and reading answers related to this topic in this site, but can't reach the point till now.

Thanks in advance,