He becomes absorbed with the search for answers, not from an ________ curiosity, but out of a deeply felt need to find out why people live.
句意：他变得对寻找答案格外执着，并不是完全出于好奇心，而是出于想要知道人们为何而活的切身需要。absolute绝对的。ideal理想的。isolated孤立的。idle闲置的。因此选B。