Assuming the use of a post$-$test only design, the notation for the experimental design in the case is

$$

$$

Question $8$ options:

a$)$

R X O

R X O

R X O

R X O

b$)$

N X O

N$$ O

N X O

N$$ O

c$)$

R$$ O$$ X$$ O

R$$ O$$ O

d$)$

R O X

R O

R O X

R O