How do consumer protection laws guarantee truthful information in the marketplace? By testing the claims made about all products and services
By requiring businesses to sign a pledge to be truthful
By requiring that businesses only make claims about their products and services that can be proven
By giving prison sentences to those who make false claims​

By requiring that businesses only make claims about their products and services that can be proven.

Explanation:

A government agency is usually a permanent organization established by either a state or national government in a federal system. They are established by legislative or executive powers for oversight and administration of specific functions. Examples of government agencies are Food and Drugs Administration (FDA), Consumer Product Safety Commission, Intelligence, Finance and Communications agency, Federal Trade Commission (FTC).

The Federal Trade Commission (FTC) is an agency of the government of the United States of America saddled with the responsibility of promoting consumer protection and the enforcement of all civil antitrust laws.

Basically, the laws formulated or established by the FTC are to provide protection for consumers of various goods and services while requiring that businesses do not make false claims about them.

Hence, the consumer protection laws guarantee truthful information in the marketplace by requiring that businesses only make claims about their products and services that can be proven.