Final answer:
Creating a brochure about the product to mail or email to the grocers would most likely help the sales associate achieve her goal.
Step-by-step explanation:
Out of the given options, the form of digital publishing that would most likely help the sales associate achieve her goal of convincing three quarters of her grocers to invest in the new product is creating a brochure about the product to mail or email to the grocers.
A brochure provides detailed information about the product, showcases its features and benefits, and allows the grocers to refer back to it whenever they need. It can be mailed physically or sent through email for convenience. The brochure acts as a persuasive tool that helps the sales associate communicate the value of the new product effectively.