Final answer:
The MPPDA would have responded to Tobis-Klangfilm's patent infringement claim through legal means, but details of their specific response are not provided in the reference information.
Step-by-step explanation:
When Tobis-Klangfilm argued that Vitaphone infringed on its patent and demanded licensing fees, the Motion Picture Producers and Distributors of America (MPPDA) had to respond to these intellectual property claims. Unfortunately, the specific historical details of the MPPDA's response to Tobis-Klangfilm's claim are not offered in the provided reference information. However, it would generally involve a legal strategy either to challenge the validity of the patent claim, negotiate licensing terms, or seek a court's decision on the matter.
This process would be in line with the legal frameworks established to protect intellectual property, similar to how the Supreme Court ruled in MGM Studios v. Grokster (2005) that companies could be held liable for distributing software that enabled copyright infringement.