In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Example Input: What did the principle of inertia do for general relativity?, Context: The concept of inertia can be further generalized to explain the tendency of objects to continue in many different forms of constant motion, even those that are not strictly constant velocity. The rotational inertia of planet Earth is what fixes the constancy of the length of a day and the length of a year. Albert Einstein extended the principle of inertia further when he explained that reference frames subject to constant acceleration, such as those free-falling toward a gravitating object, were physically equivalent to inertial reference frames. This is why, for example, astronauts experience weightlessness when in free-fall orbit around the Earth, and why Newton's Laws of Motion are more easily discernible in such environments. If an astronaut places an object with mass in mid-air next to himself, it will remain stationary with respect to the astronaut due to its inertia. This is the same thing that would occur if the astronaut and the object were in intergalactic space with no net force of gravity acting on their shared reference frame. This principle of equivalence was one of the foundational underpinnings for the development of the general theory of relativity.
Example Output: one of the foundational underpinnings

Example Input: Which of the following does not have chloroplasts: plants, Konstantin Mereschkowski, or algae?, Context: Chloroplasts are one of many types of organelles in the plant cell. They are considered to have originated from cyanobacteria through endosymbiosis—when a eukaryotic cell engulfed a photosynthesizing cyanobacterium that became a permanent resident in the cell. Mitochondria are thought to have come from a similar event, where an aerobic prokaryote was engulfed. This origin of chloroplasts was first suggested by the Russian biologist Konstantin Mereschkowski in 1905 after Andreas Schimper observed in 1883 that chloroplasts closely resemble cyanobacteria. Chloroplasts are only found in plants and algae.
Example Output: Konstantin Mereschkowski

Example Input: Who would block those who did not agree to a deal?, Context: In May 2014, prior to the launch of YouTube's subscription-based Music Key service, the independent music trade organization Worldwide Independent Network alleged that YouTube was using non-negotiable contracts with independent labels that were "undervalued" in comparison to other streaming services, and that YouTube would block all music content from labels who do not reach a deal to be included on the paid service. In a statement to the Financial Times in June 2014, Robert Kyncl confirmed that YouTube would block the content of labels who do not negotiate deals to be included in the paid service "to ensure that all content on the platform is governed by its new contractual terms." Stating that 90% of labels had reached deals, he went on to say that "while we wish that we had [a] 100% success rate, we understand that is not likely an achievable goal and therefore it is our responsibility to our users and the industry to launch the enhanced music experience." The Financial Times later reported that YouTube had reached an aggregate deal with Merlin Network—a trade group representing over 20,000 independent labels, for their inclusion in the service. However, YouTube itself has not confirmed the deal.
Example Output:
YouTube