The correct answer is D. Trademarks.
A trademark is a word, phrase, logo, or symbol that identifies and distinguishes the source of the goods of one party from those of others. It is a type of intellectual property that protects the brand and reputation of a company or individual.
In the case of the Bollywood actor, he would use a trademark to protect the name and logo of his clothing line. This would prevent other companies from using the same name or logo to sell their own clothing.
Geographical indications (GIs) are a type of intellectual property that identifies a good as originating in a particular place where a given quality, reputation, or other characteristic of the good is essentially attributable to its geographical origin. For example, Champagne is a GI that identifies sparkling wine produced in the Champagne region of France.
Patents are a type of intellectual property that protects inventions. An invention is a new product or process that offers a new way of doing something, or offers a significant improvement over existing products or processes. For example, the iPhone is a patented product.
Registered designs are a type of intellectual property that protects the appearance of a product. The appearance of a product can include its shape, configuration, pattern, or ornamentation. For example, the design of a car is a registered design.
In conclusion, the Bollywood actor should use a trademark to protect the name and logo of his clothing line. This would prevent other companies from using the same name or logo to sell their own clothing.