A、  B、  C、  B本句为询问谁来更新供应商名单的Who疑问句。

When will the factory machines be delivered?
(A)They considered several factors.
(B)She’s the supervisor.
(C)After we send our payment.

Who updates the list of suppliers?
(A)Complete it by lunchtime.
(B)The secretary should know.
(C)I’ll distribute the flyers.