Which formula can be used to find the probability of four forward steps in a random walk, beginning at location 0, given ten total steps and the probability of a forward step is 0.5?a) P(4)=10!/4!(6)! ×0.5? (0.5)?a) P(4) = 10!/(6)! ×0.5? (0.5)?c) P(4)= 10!/4! ×0.5? (0.5)?d) P(4)= 5!/2!(3)! x 0.5²(0.5)³