A random variable x has mean mu and standard deviation sigma. Suppose n independent observations of x are taken and the average xbar of these n observations is computed. We can assert that if n is sufficiently large , the distribution of xbar is approximately normal. This assertion follows from if n is sufficiently large, the distribution of xbar is approximately normal. This assertion follows from

a) the binomial experiment

b) the central limit theorem

c) the definition of sampling distribution

d) the bell curve

e) none of the above