Final answer:
A retailer's display of products on a billboard is an example of the C) informational function, central to the commercial function of advertising and marketing.
Step-by-step explanation:
When a retailer displays a huge billboard of the products of a manufacturer to attract consumers, this is an example of the retailer's C) informational function.
Advertising serves a crucial role in the commercial function by distinguishing products of one firm from those of another.
This can result in a shift of the firm's perceived demand curve, either by making it more inelastic or by causing it to shift to the right.
An effective advertising campaign can thus enable a retail firm to sell more quantity or charge higher prices—increasing profits.
Storefront displays and billboards are classic examples of how marketers aim to manipulate shoppers' emotions and create a perception of added value beyond a product's explicit utility.