if you want to examine reading skills in third grade students. Several schools are interested in collaborating with you so that you could test a...

if you want to examine reading skills in third grade students. Several schools are interested in collaborating with you so that you could test a classroom at a time would you use:

A.   Convenience sample

B.   Simple random sample

C.   Stratified random sample

D.   Stratified random sampling with proportionate representation

E.   Stratified random sampling with oversampling

F.   Cluster sampling