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.

Ex Input:
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?

Ex Output:
the complex "two-signal" activation


Ex Input:
Passage: William Henry Perkin studied and worked at the college under von Hofmann, but resigned his position after discovering the first synthetic dye, mauveine, in 1856. Perkin's discovery was prompted by his work with von Hofmann on the substance aniline, derived from coal tar, and it was this breakthrough which sparked the synthetic dye industry, a boom which some historians have labelled the second chemical revolution. His contribution led to the creation of the Perkin Medal, an award given annually by the Society of Chemical Industry to a scientist residing in the United States for an "innovation in applied chemistry resulting in outstanding commercial development". It is considered the highest honour given in the industrial chemical industry. Question: Which award is named after the discoverer of the dye?

Ex Output:
Perkin Medal


Ex Input:
Passage: Some definitions of southern Europe, also known as Mediterranean Europe, include the countries of the Iberian peninsula (Spain and Portugal), the Italian peninsula, southern France and Greece. Other definitions sometimes include the Balkan countries of southeast Europe, which are geographically in the southern part of Europe, but which have different historical, political, economic, and cultural backgrounds. Question: What is the name for the stretch of land on which Spain and Portugal are located?

Ex Output:

Iberian peninsula


