Answer:
The type of intellectual property involved in this case is copyright protection. The type of defense that Duplos may use is the doctrine of fair use, however, the court may not accept this defense and claim that Duplos is not making fair use of the published texts.
Step-by-step explanation:
As seen in the question above, Duplos used material from Ebooks and other companies in an inappropriate manner. This is because in addition to not having authorization to publish the texts of these companies, it did not pay the necessary royalts to use these texts. For this reason, we can say that Duplos hurt the intellectual property of these companies in relation to the copyright of these texts.
This case would likely be brought to court, where Duplos would claim to be within the doctrine of fair use as a defense. This doctrine claims to copy texts from other companies, it is being made for limited use. However, the court would probably not accept that the fair use doctrine applies to this case.