2. Assuming that the average case complexity for linear search is computed using indicator random variables, which of the following is NOT a feasible structure for the indicator random variable? a. X, = 1 if the ith iteration is done, o otherwise View original b. X; = 1 if the ith position contains the element to be searched, o otherwise c. X; = 1 if the ith position does not contain the element to be searched, o otherwise d. X; = 1 if the ith comparison is done, o otherwise e. All are valid indicator random variables