Which expression should be used to estimate the answer to this story problem? Travis planned to watch 4 dogs while his neighbors were out of town for a week. Each dog would need to eat 612 ounces of dog food. How many ounces of dog food were needed for all the dogs? A. 600 + 4 B. 600 – 4 C. 600 × 4 D. 600 ÷ 4