【单选题】

Although he was ------- in his efforts to persuade us of the justness of his cause, his past history, ...... with failures, prevented us from being any more than skeptical at his words.
A．(A) tireless … marred

B．(B) sage … coupled
C．(C) resourceful … immaculate
D．(D) unassuming … tinged
E．(E) unyielding … touched