—Could you please tell me ________? 　

—Sorry, I don't know. I was not at the meeting. 　[ ]

A. what the headmaster says at the meeting

B. what the headmaster said at the meeting 　　

C. what does the headmaster say at the meeting

D. what did the headmaster say at the meeting　　

发芽时先长出的为芽，以芽长1.0～2.0cm为标准。