$$\text{A}$$. $$2+1+3=6=2\times3$$;  $$\text{B}$$. $$2+1+4=7$$, and $$7$$ is not a multiple of $$3$$;  $$\text{C}$$. $$2+1+6=9=3\times3$$;  $$\text{D}$$. $$2+1+9=12=4\times3$$.  We choose $$\text{B}$$. 
Which of the followings is not a multiple of $3$? 
1. $213$ 
2. $214$ 
3. $216$ 
4. $219$ 