$\sqrt{21}$ aşağıdaki aralıklardan hangisinin bir elemanıdır?
A) $\left(4,\dfrac{21}{5}\right)$ B) $\left(\dfrac{21}{5},\dfrac{22}{5}\right)$ C) $\left(\dfrac{22}{5},\dfrac{23}{5}\right)$
D) $\left(\dfrac{23}{5},\dfrac{24}{5}\right)$ E) $\left(\dfrac{24}{5},5\right)$