Lead Time Is a Relevant Concept for Which of the Following

Lead time is a relevant concept for which of the following reasons?

A) A continuous strategy for lead time spreads advertising evenly over the campaign.
B) If the strategy for lead time works,there will be a carryover effect from past ads.
C) The further out space or time is purchased,the better the placements and prices secured.
D) The lead time for ad placement determines how many weeks the campaign will run.
E) Lead time is a method for specifying how the advertising budget has been allocated.