For each scenario below, determine whether an experiment or an observational study would be best. An online merchant wants to know the average number of days required for their shipping company to deliver an in-state order. A dermatologist wants to know whether a new lotion more effectively treats a certain type of skin rash. A grocery store manager wants to use discount card data to determine the percentage of shoppers that live in a certain ZIP code. A personal trainer wants to determine whether the use a new type of herbal supplement leads to an increased rate of muscle development. A farmer wants to know which brand of fertilizer is best for growing strawberries. A. Observational Study B. Experiment