A Biased Estimator May Be Preferable to an Unbiased Estimator

A biased estimator may be preferable to an unbiased estimator if:

A) the unbiased estimator has substantially less variability than the biased one.
B) the biased estimator has more variability than the unbiased one.
C) the biased estimator has substantially less variability than the unbiased one.
D) The only occasion where one would use a biased estimator is if an unbiased estimator did not exist.