Final answer:
The statement in question d refers to the significance of mental positioning as discussed in the book 'Positioning: The Battle for Your Mind' by Al Ries and Jack Trout.
Step-by-step explanation:
The statement in question d, 'The statement underscores the significance of mental positioning.' In the book 'Positioning: The Battle for Your Mind' by Al Ries and Jack Trout, the authors discuss the importance of mental positioning. Mental positioning refers to how a brand or product is perceived in the minds of consumers. It focuses on creating a unique and favorable image for a product or brand in order to stand out from competitors and occupy a distinct position in the consumer's mind.