Final answer:
Surnames are generally not eligible for trademark protection as they are often viewed as too generic and could limit other individuals with the same surname from conducting business. Option a.
Step-by-step explanation:
The aspect that is NOT generally eligible for trademark protection is surnames (a). Trademarks can be words, symbols, designs, or a combination of these that distinguish the goods or services of one entity from those of others. Trademark protection is granted to these elements when they are used in commerce and are distinctive. Commonly used surnames, on the other hand, are not typically eligible for trademark protection as they are often too generic and could potentially restrict other individuals with the same surname from doing business.
For example, distinctive figures like the Nike 'swoosh', the specific shape of a Coca-Cola bottle, or the decorative design of a McDonald's restaurant (trade dress) can be trademarked because they are distinctive and recognized by consumers as identifying a particular source of goods or services.
Trade dress, which pertains to the visual appearance of a product or its packaging, can also be trademarked if it serves the same function as a trademark, which is to identify the source of the product to consumers. The same holds true for words, shapes, and designs or logos used as identifying marks. However, surnames are typically not unique enough to be granted protection without showing that they have acquired distinctiveness through extensive use in the market.