The parts P, Q, R, and S of the following sentence have been jumbled. Choose the order that forms a coherent sentence: The Regent P: released Voltaire Q: having discovered that he had imprisoned R: an innocent man S: and gave him a pension.

Introduction / Context:
This sentence refers to a historical event involving the Regent and the writer Voltaire. The structure combines a participial phrase explaining the reason for an action, the central action itself, and an additional action. The test is whether you can correctly position the participial clause "having discovered that he had imprisoned an innocent man" before the main clause that tells us what the Regent did.

Given Data / Assumptions:
The fragments are:
- P: released Voltaire
- Q: having discovered that he had imprisoned
- R: an innocent man
- S: and gave him a pension
The sentence starts with "The Regent".

Concept / Approach:
In English, a common pattern is to place a reason giving participial phrase before the main clause. Here, "having discovered that he had imprisoned an innocent man" explains why the Regent acted as he did. That phrase must be built from Q and R. It should then be followed by the main verb phrase "released Voltaire" and then by "and gave him a pension" to add the further action. So the logical order is Q R P S.

Step-by-Step Solution:
Step 1: Begin with the subject: "The Regent". Step 2: Attach Q "having discovered that he had imprisoned". This introduces the cause in participial form. Step 3: Add R "an innocent man" to complete the object of "had imprisoned". Now we have "The Regent, having discovered that he had imprisoned an innocent man". Step 4: Follow with P "released Voltaire", the first main action taken after this discovery. Step 5: Add S "and gave him a pension" to mention the second action. Step 6: The full sentence reads "The Regent, having discovered that he had imprisoned an innocent man, released Voltaire and gave him a pension."

Verification / Alternative check:
Check this sequence against the options. Q R P S is listed as option D. If we instead tried P Q R S, the sentence would start "The Regent released Voltaire having discovered that he had imprisoned an innocent man and gave him a pension", which is not wrong but makes the cause effect relationship less clear and is stylistically weaker. The exam question, however, points you toward placing the participial clause near the beginning for better clarity.

Why Other Options Are Wrong:
- "P Q R S": delays the explanation of why Voltaire was released and can cause ambiguity over whether the Regent or Voltaire discovered the error.
- "P R S Q" and "Q R S P": both result in orderings where either the participial phrase is split unnaturally or the main verb is postponed too long.

Common Pitfalls:
A typical difficulty with participial phrases is misplacing them so that they appear to modify the wrong subject. Placing "having discovered that he had imprisoned an innocent man" right after "The Regent" makes it clear that the Regent made the discovery, not Voltaire. Always try to position such phrases next to the noun they logically modify to avoid dangling modifiers.

Final Answer:
The best sequence is Q R P S, which produces a clear and well structured sentence about the Regent and Voltaire.