Rearrange the parts to form a meaningful sentence: "Developing countries ___ should question the rationale ___ for such a registry ahead ___ of a negotiated outcome on this issue."

Introduction / Context:
This sentence rearrangement question involves policy language commonly seen in international negotiations. The fragments describe what developing countries should do regarding a proposed registry. You must arrange the parts P, Q, and R after the starting phrase "Developing countries" so that they create a grammatically correct and logically coherent sentence.

Given Data / Assumptions:

• Starting phrase: "Developing countries"
• Part P: "should question the rationale"
• Part Q: "for such a registry ahead"
• Part R: "of a negotiated outcome on this issue"
• We assume the sentence discusses whether to accept a registry before a formal negotiated settlement.

Concept / Approach:
The natural structure in English for this idea is: "Developing countries should question the rationale for such a registry ahead of a negotiated outcome on this issue." First we need a modal verb phrase "should question the rationale" directly after the subject. Then we specify the rationale "for such a registry" and attach "ahead of a negotiated outcome on this issue" to show that the registry is being proposed before final negotiations. Thus, the fragments must be placed so that P follows the subject, Q describes the rationale, and R continues Q logically.

Step-by-Step Solution:
Step 1: The subject is "Developing countries". Immediately after a subject, it is normal to have a verb or a verb phrase. Part P "should question the rationale" begins with "should", a modal auxiliary, so it fits naturally here. Step 2: Combine the subject and P to get "Developing countries should question the rationale ...". Step 3: Next, we need to describe the rationale. Part Q "for such a registry ahead" begins with "for", which naturally follows "the rationale". Together they read "the rationale for such a registry ahead ...". Step 4: We still need a phrase that completes the idea of "ahead". Part R "of a negotiated outcome on this issue" completes the collocation "ahead of", giving "ahead of a negotiated outcome on this issue". Step 5: Combine all parts: "Developing countries should question the rationale for such a registry ahead of a negotiated outcome on this issue." Step 6: This final sentence is grammatically correct and logically clear, so the correct order is P followed by Q and then R, that is PQR.

Verification / Alternative check:
Test an alternative, for example QRP: "Developing countries for such a registry ahead of a negotiated outcome on this issue should question the rationale." This is awkward, interrupts the normal subject verb order, and misplaces modifiers. Similarly, QPR and RPQ create unnatural structures such as starting with prepositional phrases where a main verb is needed. The combination with P first is the only one that gives a standard English sentence structure.

Why Other Options Are Wrong:
QRP begins with "for such a registry ahead", which cannot directly follow "Developing countries" as a subject without a verb. QPR places "for such a registry ahead" immediately after the subject and before the main verb phrase, resulting in a disjointed sentence. RPQ and PRQ either break the phrase "ahead of" or separate "rationale" and "for such a registry" in ways that disrupt normal collocations. Only PQR maintains the subject followed by a modal verb and then a well formed prepositional phrase.

Common Pitfalls:
Many candidates focus only on the prepositions "for" and "of" without looking at the main verb position. A reliable strategy is to first identify where the main verb or modal verb phrase must stand immediately after the subject. Then, examine prepositional phrases like "for such a registry" and "ahead of a negotiated outcome" and keep their internal structure intact. This method helps prevent confusion when multiple prepositions appear.

Final Answer:
The correct order of the parts is PQR, yielding: "Developing countries should question the rationale for such a registry ahead of a negotiated outcome on this issue."