【单选题】

As Socrates was a man of much dignity, with an______face, it was______to say whether he felt inwardly glad that the end had finally come, or felt sad over the result, and was too manly to show it
A．(A) obtuse… difficult

B．(B) imperturbable … elementary
C．(C) unassuming … intriguing
D．(D) impassible … impossible
E．(E) authoritative … challenging