It is important that his company definitely（ ）us when it is able

It is important that his company definitely（ ）us when it is able to deliver the ordered goods.
A、tell
B、tells
C、told
D、must tell
【正确答案】：A
【题目解析】：他们公司明确告诉我们什么时候交付订购的货物非常重要。