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: Nigeria is divided into thirty-six states and one Federal Capital Territory, which are further sub-divided into 774 Local Government Areas (LGAs). The plethora of states, of which there were only three at independence, reflect the country's tumultuous history and the difficulties of managing such a heterogeneous national entity at all levels of government. In some contexts, the states are aggregated into six geopolitical zones: North West, North East, North Central, South East, South South, and South West. Question: What non-state area does Nigeria have?

Ex Output:
Federal Capital Territory


Ex Input:
Passage: In 1983, the Antarctic Treaty Parties began negotiations on a convention to regulate mining in Antarctica. A coalition of international organizations launched a public pressure campaign to prevent any minerals development in the region, led largely by Greenpeace International, which established its own scientific station—World Park Base—in the Ross Sea region and conducted annual expeditions to document environmental effects of humans on Antarctica. In 1988, the Convention on the Regulation of Antarctic Mineral Resources (CRAMRA) was adopted. The following year, however, Australia and France announced that they would not ratify the convention, rendering it dead for all intents and purposes. They proposed instead that a comprehensive regime to protect the Antarctic environment be negotiated in its place. The Protocol on Environmental Protection to the Antarctic Treaty (the "Madrid Protocol") was negotiated as other countries followed suit and on 14 January 1998 it entered into force. The Madrid Protocol bans all mining in Antarctica, designating Antarctica a "natural reserve devoted to peace and science". Question: When did negotiations start to regulate mining in Antarctica?

Ex Output:

1983