1) Skin cancer caused by UV radiation.
2) Far fewer adults are INTENTIONALLY exposed to UV radiation today than they were 20 years ago.
3) Hence number of cases of Skin Cancer should reduce.
4) Paradoxically, it remains stable.
4 answer choices helps explain why. 1 answer choice will have no effect.
A: Because of decreasing levels of ozone in the upper atmosphere, more people are now exposed accidentally to excessive UV sunlight.
Accident exposure is high thereby causing more skin cancer. Helps in answering WHY. Eliminate
B: People who continue to intentionally expose themselves to UV sunlight are absorbing larger does of the harmful radiation than the average sun tanner did in the past.
More exposure means higher rate of cancer. Helps in answering WHY. Eliminate.
C: Levels of UV radiation from sources other than sunlight are increasing every year.
People are still exposed to higher sunlight from other sources thereby causing higher rate of cancer. Helps in answering WHY. Eliminate.
D: While fewer women are intentionally exposing themselves to UV sunlight, the number of men doing so has increased significantly.
Suppose previously 100 adults where exposing themselves to sunlight. Of 100, 50 were men and 50 were women. According to passage, now far fewer adults expose themselves intentionally. Let now there be only 70 adults who exposes to sunlight. Of that, number of women who exposes be 10 and number of men who exposes be 60. Hence now there is a significant number of men who exposes to sunlight than there are women. BUT overall only 70 adults expose to sunlight compared to 100 previously. With a cancer rate of 50% now you would expect only 35 to be having cancer than previously 50. Hence doesn't help us solve paradoxical question.
E: In most victims, skin cancer is linked to exposures to UV sunlight that occurred up to 30 years before the onset of the disease.
Helps explain why we still see a stable number of cancer patient. Because these patient have been exposed to sunlight 30 years ago. Eliminate.
My dad once said to me: Son, nothing succeeds like success.