Ans: C
A is not true. The mode of the distribution is the datum has the highest frequency, which is $7$.
A is not true. The mode of the distribution is the datum has the highest frequency, which is $7$.
B is not true. Note that there are $116$ data in the distribution. Therefore, the median
$\begin{array}{cl}
= & \dfrac{\text{the $58$th datum} + \text{the $59$th datum}}{2} \\
= & \dfrac{7 + 7}{2} \\
= & 7
\end{array}$
C is true. Note that there are $116$ data in the distribution. Therefore, the lower quartile
$\begin{array}{cl}
= & \dfrac{\text{the $29$th datum} + \text{the $30$th datum}}{2} \\
= & \dfrac{6 + 6}{2} \\
= & 6
\end{array}$
D is not true. Note that there are $116$ data in the distribution. Therefore, the upper quartile
$\begin{array}{cl}
= & \dfrac{\text{the $87$th datum} + \text{the $88$th datum}}{2} \\
= & \dfrac{8 + 8}{2} \\
= & 8
\end{array}$
