Rank the Exponential,degenerate,Erlang (K = 2),and Erlang (K = 4)distributions

Multiple Choice

Rank the exponential,degenerate,Erlang (k = 2) ,and Erlang (k = 4) distributions from highest to lowest variability,given the same mean.

A) degenerate,Erlang (k = 2) ,Erlang (k = 4) ,exponential.
B) degenerate,Erlang (k = 4) ,Erlang (k = 2) ,exponential.
C) exponential,Erlang (k = 2) ,Erlang (k = 4) ,degenerate.
D) exponential,Erlang (k = 4) ,Erlang (k = 2) ,degenerate.
E) none of the above.