The following questions present a sentence, part of which or all of which is underlined. Beneath the sentence, you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.
These questions test correctness and effectiveness of expression. In choosing your answer, follow the requirements of standard written English; that is, pay attention to grammar, choice of words, and sentence construction. Choose the answer that produces the most effective sentence; this answer should be clear and exact, without awkwardness, ambiguity, redundancy, or grammatical error.
The gap in the ozone layer over the North Pole can expand each summer enough that it exposes regions as far south as Sweden by heightened UV radiation, also increasing rates of skin cancer in the northern regions by as much as 50 percent.（）
A. that it exposes regions as far south as Sweden by heightened UV radiation, also increasing
B. that regions as far south as Sweden have been exposed to heightened UV radiation, as well as having increased
C. to expose regions as far south as Sweden to heightened UV radiation, increased
D. to expose regions as far south as Sweden to heightened UV radiation and increase
E. that exposure to heightened UV radiation in regions as far south as Sweden, as well as increasing
