Which of the following exemplifies the empirical method?Which of the following…

Which of the following exemplifies the empirical method?
Dr. Sarkeesian observes and records how watching cartoons influences heart rates.
A student writes a letter to his professor requesting a change in course policy.
Dr. Hysock-Witham decides to start her course later because so many students arrive late.
A student in a psychology class writes his term paper on whether or not fish feel pain.