单选题 Clients are invited to write______ call for additional information.

A、 (A) but
B、 (B) or
C、 (C) not
D、 (D) either

【正确答案】 B

【答案解析】Or indicates a choice between items. Choice (A) indicates a contrast between items. Choice (C) is a negative, not a conjunction. Choice (D) is usually paired with or.