When Testing Theories,economics Is Disadvantaged Compared to the Natural Sciences

Multiple Choice

When testing theories,economics is disadvantaged compared to the natural sciences because

A) it deals with human behaviour and thus is not open to empirical testing.
B) it is usually not possible to conduct controlled experiments in economics,in contrast with certain other sciences.
C) economic hypotheses cannot be accepted with complete certainty,by contrast with the other sciences.
D) economic variables do not change enough to provide reliable data for testing hypotheses.
E) some economic variables are determined within the theory.