单选题
[阅读理解]The ISU won't finally approve the new system until it meets in June but already UK Sport， the British Government's sports body， has expressed reservations. “I remain to be convinced that the random selection system would offer the guarantees that everyone concerned with ethical sport is looking for”， says Jerry Bingham， UK Sport's head of ethics（伦理）。
What does Jerry Bingham express by saying “I remain to be convinced”？
A.His anger.
B.His criticism.
C.His agreement.
D.His doubt.
正确答案：D
答案解析：本段Jerry Bingham说我仍然需要进一步确信，所以他是持怀疑态度的。