문제 내용: A growing number of people are seeking medical attention for vitamin D deficiency, a common condition among those who spend a lot of time indoors. It is well known that vitamin D deficiency can affect one's muscles, bones and immunity and is even associated with cancer. Vitamin D is produced by the body in response to skin being exposed to sunlight. A lot of women, however, wear sunscreen before they go out, and this often makes it more difficult for their body to produce vitamin D as
선택지 1: many types of sunscreen may contain beneficial substances
선택지 2: sunscreen can block vitamin D-producing ultraviolet rays
선택지 3: their sunscreen is professionally prescribed
선택지 4: they exercise on a regular basis