PT158 · S2 · Q13 The widespread use of encryption

This answer restates a premise of the argument, not the main conclusion. The statement that most private correspondence and diaries will be stored as encrypted text is presented as a factual prediction about future technology adoption. It is one link in the causal chain that supports the main conclusion. The main conclusion is about the consequence of this encryption — the end of biographical history. This answer describes the cause (encrypted storage), not the effect (the end of biographical writing). In the argument's structure, this fact is offered as evidence for why biographical history will suffer, not as the main point the argument is trying to establish.

This answer says historians will probably not have access to much private correspondence and diaries of public figures in the future. While this is a reasonable inference from the argument, it functions as an intermediate conclusion or unstated implication — not the main conclusion. The argument's main conclusion is about the broader consequence of this inaccessibility: the end of biographical history. This answer describes a step in the causal chain (historians lose access) rather than the final result (biographical history ends). The main conclusion is the ultimate destination of the reasoning; this answer stops one step short.

This answer says biographers' access to interesting material will be determined by the availability of passwords. While this is implied by the argument, it is an intermediate conclusion, not the main conclusion. The argument uses this point — that password access will control information availability — to support its broader claim that biographical history will virtually end. This answer describes a mechanism or condition, not the ultimate consequence. Additionally, this is a classic "last-claim trap": test-takers sometimes select the last statement in an argument as the main conclusion simply because it appears at the end. But in this argument, the main conclusion appears in the first sentence, and the final sentence provides supporting detail.

This answer says public figures' private correspondence and diaries are the most interesting and revealing sources for biographical history. The argument does say that this material constitutes biographers' "principal sources" and refers to it as "the most interesting, revealing material." However, this is a background premise or assumption of the argument, not its main conclusion. The argument uses this claim to explain why the loss of access to encrypted documents would be devastating to biographical history. It is a building block, not the final structure. The main conclusion is about the consequence of losing access to these sources: the end of biographical history writing.