A. It has removed many of the material obstacles to the pursuit of the good life from the majority of mankind in those countries at a high level of technical development.

B. But it has exposed us to new dangers, not the obvious dangers of new weapons of destruction,  but the much more serious ones of a purely materialist view of life.

C. The growth of science and technology has conferred obvious and immense benefits upon the community.

D. It has also, as we too often forget, made possible new and daring adventures of the mind.

The best arrangement here would be  CADB. The reasoning is that Sentence C starts with the big picture: it introduces the general theme of scientific and technological benefits. We then zoom into specific examples (A & D) by mentioning the benefits - first in material improvements (Sentence A), then in intellectual advancements (Sentence D). To finally sum up the discussion, we introduce a counterpoint (Sentence B) where we present a critical viewpoint by highlighting the potential negative consequences.

Hence, Option A is the correct choice.