The hourly wages (in ₹) of eight workers are 120, 130, 135, 140, 150, 155, 160, and 165. A new trainee earning ₹200 joins the group. Which measure of dispersion is certain to increase after including the trainee?
(a) Standard deviation only
(b) Both range and standard deviation
(c) Range only
(d) Neither range nor standard deviation