9. Multiple Answer: Which of the following is/are likely reasons that healthcare spending has increased dramatically in the US. over the past several decades? Select ALL answers that apply. Briey explain the selected answer(s) (no need to explain the answers not selected). (2 points) a. The US. healthcare ination rate is lower than the general ination rate b. The US. is using more advanced and expensive technology than in the past 0. The US. population is healthier than in the past d. The US. population is aging and has a higher share of elderly people than in the past