A dolphin swims 665,280 feet in 3 hours. Use the formula d = rt, where d represents distance, r represents rate, and t represents time, to answer the following questions. Show your work.

Part A: Rearrange the distance formula, d = rt, to solve for rate. (2 points)

Part B: Find the dolphin's rate in feet per hour. (3 points)

Part C: Find the dolphin's rate in miles per hour. (3 points)

Part D: Which unit, feet, or miles, makes more sense to use in this scenario, and why? (2 points)