【名词&注释】
中国联通(china unicorn)、接通率(percentage of successful connections)、国际漫游、客户服务水平(customer service level)
[单选题]服务水平指20s内的人工接通率。VIP客户服务水平(customer service level)的合规值是:()
A. A、≥85%/20s。 B. B、≥80%/20s C. C、≥75%/20s D. D、≥70%/20s