Question

7 a(n) ______ makes it difficult to determine whether an experimental outcome is due to the applied treatment a uncooperative subject b confounding variable c mr. milford d error

Explanation:

A confounding variable is an extraneous factor in an experiment that correlates with both the independent (treatment) and dependent (outcome) variables, making it impossible to tell if the outcome comes from the treatment or this unaccounted variable. The other options do not fit: an uncooperative subject affects participation but not causal attribution, Mr. Milford is irrelevant, and general error does not specifically obscure treatment-outcome links in this targeted way.

Answer:

B. confounding variable