( ) A mystery unsolved, subject to endless speculations, has the power to haunt us as long as memory persists.
(A) We will keep on thinking and wondering about an unsolved mystery as long as we remember it.
(B) A mystery solved will haunt us persistently.
(C) A mystery is likely to speculate endlessly when we still have power.
(D) In order to solve a mystery, we should just forget about it.
Step 1：瀏覽句意，找出主結構：“A mystery has the power to haunt us.” (難以理解的事物有困擾我們的力量)。