what is the correct answer ?

6.8 What will the browser display if the following script is executed and the user enters 5 at both prompts? script type = "text/javascript" > var firstNumber = window prompt ( "Enter an integer", "0" ); var secondNumber= window prompt( "Enter an integer", "0"); var thirdNumber; thirdNumber = firstNumber + secondNumber; document.write( thirdNumber ); // > /script> a) nothing b) 0 c) 10 d) 55