When I have received business plans, the very best responses come from people who have looked at the risks and have an answer for every question. What you never want is to throw a scenario at your plan and have to answer "I don't know what I would do in that situation". You want to plan for every possible contingency, and certainly all the major risks to the ongoing success of your business.
Describe the manufacturing or operating process and associated costs. Contain believable finical projections, with key data explained and documented.
A business that makes sense and is going to be sustainable in the future is one that has that clear vision within which all the smaller parts contribute to make it successful.
It seems to have been put there to fill the need to attribute a certain sum to marketing. Make sure you are researching each point of your budget, make sure that you are giving it context and it makes proper sense within your overall plan.