The following four labelled sentences P, Q, R and S, when properly sequenced, form a coherent paragraph describing World War I. Select the most logical order.

Introduction / Context:
This para-jumble deals with a brief description of World War I. The sentences talk about when the war began and ended, who fought, the nature of the fighting and weapons, and the final casualty figures. A well-ordered paragraph should move from basic facts to participants, then to the character of the war, and finally to its consequences.

Given Data / Assumptions:
- P: World War I began in 1914, after the assassination of Archduke Franz Ferdinand, and lasted until 1918.
- R: During the conflict, Germany, Austria-Hungary, Bulgaria and the Ottoman Empire (the Central Powers) fought against Great Britain, France, Russia, Italy, Romania, Japan and the United States (the Allied Powers).
- Q: Thanks to new military technologies and the horrors of trench warfare, World War I saw unprecedented levels of carnage and destruction.
- S: By the time the war was over and the Allied Powers claimed victory, more than 16 million people – soldiers and civilians alike – were dead.
- We assume the paragraph should first state what the war was and its time frame, then name the participants, then describe how it was fought, and finally report the scale of casualties.

Concept / Approach:
Sentence P clearly introduces World War I, giving its starting event and duration, so it is the natural opening. After we know when it happened, it makes sense to learn who fought it, which is described in R. Once the main players are introduced, Q explains the nature of warfare and technology that led to high levels of destruction. Finally, S comments on the outcome and the death toll, which ties up the description with a grim conclusion. Thus, the best sequence is P–R–Q–S.

Step-by-Step Solution:
Step 1: Start with P, which sets the historical context of World War I and mentions the assassination that triggered it.
Step 2: Follow with R, which introduces the Central Powers and Allied Powers, describing who fought on each side.
Step 3: Use Q next to explain how new technologies and trench warfare made this conflict unusually destructive.
Step 4: Close with S, which summarises the loss of life and states that the Allied Powers finally claimed victory.

Verification / Alternative check:
Reading PRQS as a paragraph gives a clear, chronological and logical progression: origin and duration (P), belligerent nations (R), type of warfare (Q), and casualties plus final victory (S). If you try PSQR or SPQR, the flow becomes less natural because the casualty figures should logically come after, not before, a description of the war's nature and participants.

Why Other Options Are Wrong:
- SPQR and SQPR: These start with casualty figures or descriptive horror before properly introducing what World War I is and who fought, which is less informative for a short summary paragraph.
- PSQR: Jumps from introduction (P) to casualties (S) and then to participants (Q, R), which is not an ideal logical order.

Common Pitfalls:
In historical para-jumbles, learners sometimes focus only on dates and assume the sentence mentioning deaths must come immediately after the introduction. However, a good historical summary usually follows the pattern: when, who, how, and what consequences. Keeping this structure in mind helps you quickly test different arrangements and choose the one that reads most like a textbook explanation.

Final Answer:
The most logical order of the sentences is PRQS.