Kayla rented a boat. There was a one-time charge of $100 plus an hourly rate of $45. Her total cost for the day was $370. Which equation, when solved for x, gives the number of hours she rented the boat? A) 45x + 100 = 370 B) 45x − 100 = 370 C) 45x + 370 = 100 D) 45x − 370 = 100