Factors of $8$ are $1, 2, 4, 8$ and factors of $12$ are $1, 2, 3, 4, 6, 12$.  The highest commom factor of $8$ and $12$ is $4$.  Dividing $8$ and $12$ by $4$ respectively, we get  $\frac{8 \div 4}{12 \div 4}$=$\frac{2}{3}$;  Write the whole and the simplified fraction together,  $3\dfrac{2}{3}$. 
What is the simplest form of $3\dfrac{8}{12}$? 

1: $3\dfrac{3}{4}$ 
2: $\frac{42}{12}$ 
3: $\frac{10}{3}$ 
4: $3\dfrac{2}{3}$ 