If we consider them to be

binary we get $1/1 + 0/1 = 1/1$, $1/2 + 1/3 = 5/6$. Lastly, we have $3/2 + 1/3 = 11/6$ which corresponds to B.

If we consider them to be

binary we get $1/1 + 0/1 = 1/1$, $1/2 + 1/3 = 5/6$. Lastly, we have $3/2 + 1/3 = 11/6$ which corresponds to B.

Here is an image