Final answer:
Levitt's concept of a fully-standardized international marketplace is not fully represented in most consumer brands today due to market diversity and varying international trade rules.
Step-by-step explanation:
The assertion that Levitt's concept of a fully-standardized international marketplace is represented in most consumer brands today is false. While global brands do pursue standardization in certain aspects, such as maintaining the brand identity and certain product characteristics, the international marketplace is too diverse for full standardization. Companies must often adapt to different markets, cultures, and regulatory environments, making the concept of a universal standardized market more aspirational than practical. Moreover, international trade rules do not mandate uniform consumer safety standards across all nations, which further contributes to the variation in product offerings and standards globally.