The correct answer is: C. Paired t-test.
A paired t-test is a statistical test that is used to compare the means of two groups that are related in some way. For example, you might use a paired t-test to compare the mean weight of two groups of people who have been on different diets for a month. The paired t-test is a more powerful test than the independent t-test, which is used to compare the means of two groups that are not related.
A chi-squared test is a statistical test that is used to compare the observed frequencies of a categorical variable to the expected frequencies. The chi-squared test is used to test for independence, goodness of fit, and homogeneity.
An ANOVA is a statistical test that is used to compare the means of three or more groups. ANOVA is a more powerful test than the t-test, which is used to compare the means of two groups.
Regression analysis is a statistical method that is used to find the relationship between two or more variables. Regression analysis can be used to predict the value of one variable based on the values of other variables.
In conclusion, the correct answer is: C. Paired t-test.