If $m$ and $n$ are integers greater than zero and $m < n$, we define $m \nabla n$ as the sum of the integers between $m$ and $n$, including $m$ and $n$. For example, $5 \nabla 8 = 5 + 6 + 7 + 8 = 26$. What is the value of $\frac{22 \nabla 26}{4 \nabla 6}$?
(a) 4
(b) 6
(c) 8
(d) 10
(e) 12
The correct option is (c).

By definition, we obtain $\frac{22 \nabla 26}{4 \nabla 6}=\frac{22+23+24+25+26}{4+5+6}=\frac{120}{15}=8$.