This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Example Input: Passage: In New York City in 1846, Alexander Turney Stewart established the "Marble Palace" on Broadway, between Chambers and Reade streets. He offered European retail merchandise at fixed prices on a variety of dry goods, and advertised a policy of providing "free entrance" to all potential customers. Though it was clad in white marble to look like a Renaissance palazzo, the building's cast iron construction permitted large plate glass windows that permitted major seasonal displays, especially in the Christmas shopping season. In 1862, Stewart built a new store on a full city block with eight floors and nineteen departments of dress goods and furnishing materials, carpets, glass and china, toys and sports equipment, ranged around a central glass-covered court. His innovations included buying from manufacturers for cash and in large quantities, keeping his markup small and prices low, truthful presentation of merchandise, the one-price policy (so there was no haggling), simple merchandise returns and cash refund policy, selling for cash and not credit, buyers who searched worldwide for quality merchandise, departmentalization, vertical and horizontal integration, volume sales, and free services for customers such as waiting rooms and free delivery of purchases. His innovations were quickly copied by other department stores. Question: What policy did the Marble Palace introduce? 
Example Output: "free entrance" to all potential customers.

Example Input: Passage: Digimon started out as digital pets called "Digital Monsters", similar in style and concept to the Tamagotchi. It was planned by WiZ and released by Bandai on June 26, 1997. The toy began as the simple concept of a Tamagotchi mainly for boys. The V-Pet is similar to its predecessors, with the exceptions of being more difficult and being able to fight other Digimon v-pets. Every owner would start with a Baby Digimon, train it, evolve it, take care of it, and then have battles with other Digimon owners to see who was stronger. The Digimon pet had several evolution capabilities and abilities too, so many owners had different Digimon. In December, the second generation of Digital Monster was released, followed by a third edition in 1998. Question: What did the Digimon pets originally start out as?
Example Output: Digital Monsters

Example Input: Passage: Hellenistic Geometers such as Archimedes (c. 287 – 212 BC), Apollonius of Perga (c. 262 – c. 190 BC), and Euclid (c. 325 – 265 BC), whose Elements became the most important textbook in mathematics until the 19th century, built upon the work of the Hellenic era Pythagoreans. Euclid developed proofs for the Pythagorean Theorem, for the infinitude of primes, and worked on the ﬁve Platonic solids. Eratosthenes used his knowledge of geometry to measure the circumference of the Earth. His calculation was remarkably accurate. He was also the first to calculate the tilt of the Earth's axis (again with remarkable accuracy). Additionally, he may have accurately calculated the distance from the Earth to the Sun and invented the leap day. Known as the "Father of Geography ", Eratosthenes also created the first map of the world incorporating parallels and meridians, based on the available geographical knowledge of the era. Question: Who worked on the five Platonic solids?
Example Output:
Euclid