A new sunscreen has been developed that is supposed to be more effective at preventing sunburn. 30 participants spray one arm with the new formula and spray the other arm with the leading formula. After 4 hours in the sun, their skin is evaluated for any redness.What is the Independent Variable?a. the 30 arms with the old formulab. the 30 arms with the new formulac. Amount of rednessd. Type of sunscreene. the 15 arms with the new formula