What was the articles of confederation biggest problem? why?

"there will be differences in degree of mood elevation seen in depressed clients after receiving either cognitive-behavioral or psychoanalytic therapy."; in this hypothesis, mood elevation is the:

Cattle are herbivores by nature and feeding herbivores a diet for carnivores may have triggered a protein reaction known as a prion causing mad cow disease

Which statements are true about "evidence"? )observations which answer questions )proof that an idea is true )information for or against an idea )data to draw a conclusion