38. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage ?Later investigators found themselves confronting a new obstacle, seemingly insurmountable, as it was set by thevery laws of physics.
(A)After a while, the scientist unexpectedly discovered a new principle in physics, even though it was difficult.
(B) Subsequent studies were deterred by unforeseen physical constraints that appeared to be unsolvable.
(C) Some of the scientists were convinced that they could find even more cell parts because they were working a novelbranch of physics.
(D) Although it was too late for scientists with traditional backgrounds to tackle the problem, they were optimistic that thescientific barrier would be overcome.