Answer:
Option B is correct because the first thing is we can not register it as trademark because the requirement to register trademark is:
In this case the word bicycle is not distinctive. The word distinctive in law means that the item must be different from something else either in nature or type.
Option A is incorrect as the word bicycle is not distinctive, so it can not be registered. And if it can not be registered then it can not be protected against trademark infringement.
Option C is also incorrect as this word does not meets the requirements of trademark registration.
Option D is also incorrect because certification mark are logos of products to make the quality or nature of product clear.