Answer:
a. Trademark infringement
Explanation: The term Trademark is a name or symbol on a product that shows it was made by a particular company, and hence cannot be used by another company without permission from the company that owns the product.
Trademark infringement is the unauthorized use of a trademark or service mark. Using a trademark without getting permission from the owners or the trademark or obtaining a license to use it. t is usually used when talking about goods or products. Example of this case is competition with related goods and services as is the case in the question.