The Sampling Distribution of T Differs from the Sampling Distribution

Multiple Choice

The sampling distribution of t differs from the sampling distribution of z in that _________.

A) there is only one sampling distribution of z (the normal distribution) for all N , while there are many sampling distributions for t , depending on sample size.
B) the sampling distribution of z is more narrow, except when N equals infinity.
C) the means of the two distributions are different
D) all of these
E) a and b