In the classic Pavlov experiments investigating conditioning in dogs, the sound of a metronome (which preceded the dogs' exposure to food) is an example of a(n) _____ variable

The severity of symptoms with delirium___________

a. steadily becomes more severe over the course of a day b. becomes severe only in the evening c. fluctuates throughout the course of a day d. remains constant for the remainder of the patient's life

Why do scientists prefer the more parsimonious explanation? a. It is simpler

b. It is more interesting. c. It leads to getting better grant support. d. It avoids the burden of proof.