Which of the Following Best Describes the Sampling Distribution of the Test

Short Answer

Which of the following best describes the sampling distribution of the test statistic for a goodness-of-fit test with k categories? A. Student $t$ -distribution with $k-1$ degrees of freedom.
B. Normal distribution.
C. Chi-squared distribution with $k-1$ degrees of freedom.
D. Approximately Chi-squared distribution with $k-1$ degrees of freedom.