One Goal of Stratified Sampling Plans Is to Decrease the Amount

Multiple Choice

One goal of stratified sampling plans is to decrease the amount of variability in each stratum. This can be accomplished by

A) making the strata internally heterogeneous.
B) increasing the amount of sampling error.
C) decreasing the magnitude of the overall sample mean.
D) making the strata internally homogeneous.
E) using a 99% confidence level instead of a 95% confidence level.