Last Word"Patent trolls:" a. block firms from acquiring patents on intellectual property.
b. buy up patents in order to collect royalties and sue other companies.
c. legally challenge new patent applications in an effort to extract rents.
d. promote innovation by keeping firms from having a stranglehold on intellectual property.

b. buy up patents in order to collect royalties and sue other companies.

Explanation:

Patent can be defined as the exclusive or sole right granted to an inventor by a sovereign authority such as a government, which enables him or her to manufacture, use, or sell an invention for a specific period of time.

Generally, patents are used on innovation for products that are manufactured through the application of various technologies.

Patent trolls buy up patents in order to collect royalties and sue other companies. This ultimately implies that, patent trolls are individuals or companies that are mainly focused on enforcing patent infringement claims against accused or potential infringers in order to win litigations for profits or competitive advantage.

Hence, patent trolls are not interested in using the patent to produce new products or be innovative, rather they are for profits, licensing fees or to stifle competition.

answer; commerce clearing house;

answer; trojan horse;