What will be the expected output of the following lines of code? let printString = (string, callback) => { set Timeout( () => { } ); console.log(string); callback(); }, 3 * 1000 printString("1", () => (console.log("callback")}) printString("2", () => {console.log("callback"))) printString ("3", () => (console.log("callback"))) //line 1 //line 2 //line 3