Final answer:
Assumptions underlying the marketing plan should be checked frequently to ensure accuracy and relevance.
Step-by-step explanation:
The marketing plan assumptions need to be checked frequently to ensure their accuracy and relevance. This is important because the market conditions and consumer preferences can change over time, and assumptions that were valid in the past may no longer hold true.
For example, let's say a marketing plan assumes that the target audience for a product is primarily young adults. However, if the market research shows that the demographics have shifted and the target audience is now older adults, the assumptions underlying the marketing plan need to be adjusted accordingly.
By regularly checking and updating the assumptions, the marketing plan can stay aligned with the current market realities and increase its effectiveness in reaching the intended audience.