help please

4. Indicate whether a researcher would conduct an experiment or a correlational study when studying: (a) whether different amounts of caffeine consumed in 1 hour influence speed of completing a task; (b) the relationship between number of extracurricular activities and GPA; (c) the relationship between the number of pairs of sneakers owned and the person's athleticism; (d) how attractive men rate a woman when she is wearing one of three different types of perfume; (e] the relationship between GPA and the ability to pay off student loans; (f) the influence of different amounts of beer consumed on a person's mood