Answer: Marketing
Explanation: A marketing plan represents part of a business plan outlining marketing tactics and strategies to be employed in other let the world know about your product and services.
A marketing plan is very crucial to a company's success. A failed marketing strategy obviously indicates the failure of a business.
A marketing plan outlines the target market or environment, objectives, tactics required to capture our intended audience or client, best medium of reaching out to our clients and promotional offers which makes our product and services effectively rival those of our competitors.
A good marketing plan / strategy is at the heart of a very successful business.