The utility of the Central Limit Theorem (CLT) with regards to related a sample based estimate of a population value (mean, proportion, incidence rate) is:

a. The CLT guarantees that the true value of the population quantity will always fall within 2 standard errors of the sample estimate.

b. The CLT is actually only useful and applicable if the individual observations are normally distributed in the population from which the sample was taken.

c. The CLT allows us to predict how a sample based estimate will behave in relation to the true population value across multiple random samples from this population.

d. The CLT ensures that results of a sample based study are scientifically valid.