$$C\cup D=\left\{10,20,30,50,80,90\right\}$$

$$C\cup D=\left\{10,20,50,80,90\right\}$$

$$C\cup D=\left\{10,20,30,50,80\right\}$$

$$C\cup D=\left\{10,20,30,40,50,80,90\right\}$$

$$R\cup S=\left\{1,2,3,4,5,6,7\right\}$$  

$$R\cup S=\left\{1,2,3,4,5,6,7,8,13\right\}$$  

$$R\cup S=\left\{1,2,3,5,8,13\right\}$$  

$$R\cup S=\left\{4,6,7,8,13\right\}$$