Which statement will return the mathematical sum of these variables?

Suppose you define two variables as follows:
var x = 5;
var y = “5”;
Which statement will return the mathematical sum of these variables?

A.
alert(x + int(y));

B.
alert(x + parseInt(y));

C.
alert(x + y);

D.
alert((int)x + (int)y);

Explanation: