For a certain experiment the available experimental units are 8 people; four females (f) and four males(m). use (1f,2f,3f,4f) to denote the females and (1m,2m3,m,4m) to denote the males. there are to be four treatment groups: A, B,C, and D. if a randomized block design is used with the experimental units blocked by gender, which assignment of treatments is correct A: A(1f, 3m), B(2f,2m), C(3f,1m), D(4f,4m)
B: A(2m,1m), B(1f,2m), C(3f,3m), D(4f,4m)
C: A(3m,1m), B(2f,4f), C(3f, 1f), D(4m,2m)
D: A(1f,3f), B(2f, 2m), C(4f,1m), D(4m,3m)