In a Chi-Squared Goodness-Of-Fit Test, If the Expected Frequencies $e _ { i }$

In a chi-squared goodness-of-fit test, if the expected frequencies $e _ { i }$ and the observed frequencies $f _ { i }$ were quite different, which of the following is the best conclusion? $\begin{array}{|l|l|}\hline \text { A. } & \text { Null hypothesis is false, and reject } \mathrm{H}_{O} \\\hline \text { B. } & \text { Null hypothesis is true, and retain } \mathrm{HO} . \\\hline \text { C. } & \text { Alternative hypothesis is false, reject } \mathrm{H}_{\mathrm{A}} \\\hline \text { D. } & \text { Chi-squared distribution is invalid, use } t \text {-distribution instead. } \\\hline\end{array}$