Answer:
Option B
Explanation:
(B) This is a rather long and involved sentence and the correct answer can be got by inserting each of the answer choices in the blank, and testing which of the resulting sentences makes Logical sense. If scientists have a considerable interest in the possibility that increasing levels of atmospheric carbon-di-oxide can cause long-term warming affects, it is illogical to say that such interest will be sustained only until the current warming trend exceeds the range of normal climatic fluctuations. In fact, scientific interest in the phenomenon should be logically expected to increase if the current warming trend exceeds the range of normal climatic fluctuations. So, (A) is wrong. Since long-term warming trends caused by increasing levels of carbon-dioxide are detrimental to life on earth, scientists cannot be having an enthusiasm for such a possibility. So, (C) is wrong. While scientists would certainly worry about the trend, such worry cannot be only upto the period until the curre
