Answer:
d. public relations strategy.
Explanation:
Public relations strategy is the basic marketing need to be done on a long run, in order to connect with public and to prove that the company is most reliable for their needs.
It basically aims at creating awareness in the audience and public of the event about the company product.
This helps in boosting the demand of the product, getting in the lime light of people.
In the give instance also, by announcing the marathon and then placing hoardings everywhere in the marathon, creates a brand awareness in the public, also this displays the pubic connection which the company desires to establish.