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.
--------
Question: Passage: In the mid-1950s, Frank Burnet, inspired by a suggestion made by Niels Jerne, formulated the clonal selection theory (CST) of immunity. On the basis of CST, Burnet developed a theory of how an immune response is triggered according to the self/nonself distinction: "self" constituents (constituents of the body) do not trigger destructive immune responses, while "nonself" entities (e.g., pathogens, an allograft) trigger a destructive immune response. The theory was later modified to reflect new discoveries regarding histocompatibility or the complex "two-signal" activation of T cells. The self/nonself theory of immunity and the self/nonself vocabulary have been criticized, but remain very influential. Question: What property of T cells caused modification of CST?

Answer: the complex "two-signal" activation


Question: 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?

Answer: Digital Monsters


Question: Passage: By 1975 the majority of local authorities in England and Wales had abandoned the 11-plus examination and moved to a comprehensive system. Over that 10-year period many secondary modern schools and grammar schools were amalgamated to form large neighbourhood comprehensives, whilst a number of new schools were built to accommodate a growing school population. By the mid-1970s the system had been almost fully implemented, with virtually no secondary modern schools remaining. Many grammar schools were either closed or changed to comprehensive status. Some local authorities, including Sandwell and Dudley in the West Midlands, changed all of its state secondary schools to comprehensive schools during the 1970s. Question: By what year did the 11-plus exam mainly fall out of use?

Answer:
1975