单选题
Mike has already put forward his suggestion ______ a production plan should be completed next week.
【正确答案】
D
【答案解析】[考点] 同位语从句
[解析] 本句的意思是：迈克已提出了他的建议，即应该在下周完成生产计划。A production plan should be completed next week是his suggestion的同位语，由that引导，因此D. that是正确答案。