How Do the T_df and Z Distributions Differ

Multiple Choice

How do the t_df and z distributions differ?

A) There is no difference between the t_df and z distributions; they both do not have asymptomatic tails.
B) The z distribution has broader tails (it is flatter around zero) .
C) The t_df distribution has broader tails (it is flatter around zero) .
D) The z distribution has asymptotic tails, while the t_df distribution does not.