The probability that both show a green bean is $\dfrac{1}{2}\cdot \dfrac{1}{3}=\dfrac{1}{6}$. 
Abe has $1$ green and $1$ red jelly bean in his hand. Bob has $1$ green and $2$ yellow jelly beans in his hand. Each randomly picks a jelly bean to show to the other. What is the probability that the colours match? ． 
Options:
  $\dfrac{1}{2}$ 
  $\dfrac{1}{3}$ 
  $\dfrac{3}{4}$ 
  $\dfrac{1}{6}$ 
  $\frac{1}{9}$ 