HEL The Apadena at Persepolis is considered to possess elements of propaganda and persuasion. What aspect of the complex suggests persuasion instead of propaganda?
A. Delegates are shown in friezes,
B. The Persian Hall consists of accurate cultural representations from different countries,
C. The hypostyle hall is intimidating to outsiders,
D. All of the above

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

i think it is the third one.

answer; marvin gaye;