Which of the following is prohibited in dealer advertisements?

Dealer advertisements must adhere to specific regulations to ensure honesty and transparency in marketing. The prohibition on using the term "free merchandise" without conditions is in place to prevent misleading consumers who may interpret "free" differently than intended. If there are strings attached, such as minimum purchases or hidden fees, these conditions must be disclosed to avoid misleading advertising.

Additionally, advertising without showing the total cost is another critical aspect. Federal laws and guidelines, such as the Truth in Advertising principles, require that any advertisement clearly state the total price a consumer would pay, including all fees, taxes, and additional costs. This transparency allows potential buyers to make informed decisions without encountering unexpected costs later.

Making false claims about product features is strictly prohibited as well. Misrepresenting the attributes of a product can lead to consumer deception, tarnish a dealer's reputation, and result in legal ramifications.

Since all these practices violate advertising standards aimed at protecting consumers, they are collectively prohibited. Hence, the option encompassing all of them accurately represents the comprehensive nature of these regulations, reinforcing the importance of ethical advertising in the commercial modular sales industry.