In an Experiment Aimed at Evaluating the Effect of a Memory-Enhancing

Multiple Choice

In an experiment aimed at evaluating the effect of a memory-enhancing drug on the recall of a previously learned response. Either the drug or a placebo was administered to different groups of rats before the memory test. There were three trials of the memory test, and the dependent variable was the time it took the animal to make the correct response.
What assumption(s) would we need to make for this analysis?

A) The observations are independent.
B) The observations are normally distributed.
C) The animals are randomly assigned to drug treatments
D) both b and c