1) 6(1 - 5m) 2) -2(1 - 5v) 3) 3(4 + 3r) 4) 3(Gr + 8) 3157 5) 4(8n + 2) 6) -(-2-n) 8) -3(7n + 1) 7) -6(7k + 11) 10) -10(a-5) 9) -6(1 + 11b)​

Which of the following is the major negative aspect of crossover designs for research studies? a. prohibitive cost b. residual effects c-subject drepout d. incomplete randomization e. large sample size required