You are thinking of employing a t procedure to test hypotheses about the mean of a population using a significance level of 0.05. You suspect the distribution of the population is not Normal and may be moderately skewed. Which of the following statements is correct?

a. You should not use the t procedure because the population does not have a Normal distribution.
b. You may use the t procedure, but you should probably claim the significance level is only 0.10.
c. You may use the t procedure, provided your sample size is large, say, at least 40.
d. You may not use the t procedure because t procedures are robust to non-Normality for confidence intervals but not for tests of hypotheses.