The question below consists of a set of labelled sentence parts. Select the most logical order of the parts to form a coherent sentence: If there is a X – corresponding sensation Y – kind, there has to be a Z – change in brain activity of a certain.

Introduction / Context:
This is another sentence-order question that evaluates your ability to arrange jumbled parts into a clear, logical, and grammatically correct statement. The sentence deals with the relationship between changes in brain activity and corresponding sensations. To answer correctly, you must understand both the meaning and the structure of complex English sentences, especially conditional clauses starting with “If there is a …”.

Given Data / Assumptions:
- Introductory phrase: “If there is a”. - Labeled parts: X – corresponding sensation Y – kind, there has to be a Z – change in brain activity of a certain - We assume the final sentence will talk about a change in brain activity of a certain kind and a corresponding sensation.

Concept / Approach:
The natural scientific idea here is that if there is a certain change in brain activity, there will be a corresponding sensation. However, because the sentence begins with “If there is a”, the first phrase after it should be “change in brain activity of a certain kind” rather than “corresponding sensation”. That whole condition is then followed by “there has to be a corresponding sensation.” The labels must be arranged to create this structure while respecting the exact wording provided in X, Y, and Z.

Step-by-Step Solution:
1. Start with the phrase “If there is a” and test which labelled part can logically follow immediately. 2. “If there is a change in brain activity of a certain” (Z) is grammatically and logically sound because it sets up the condition. 3. The word “kind” from part Y fits after “of a certain”, giving “change in brain activity of a certain kind, there has to be a …”. 4. Finally, the phrase “corresponding sensation” (X) naturally follows “there has to be a”, completing the sentence. 5. Therefore, the complete sentence is: “If there is a change in brain activity of a certain kind, there has to be a corresponding sensation.” 6. This order corresponds to ZYX.

Verification / Alternative check:
Write the full sentence with ZYX: “If there is a change in brain activity of a certain kind, there has to be a corresponding sensation.” This is a coherent scientific statement that flows smoothly. If you try ZXY, you get “If there is a change in brain activity of a certain corresponding sensation kind, there has to be a …” which is clearly wrong. Similarly, orders starting with Y or X break the conditional structure and sound ungrammatical. Comparing these alternatives proves that ZYX is the only acceptable order.

Why Other Options Are Wrong:
- ZXY: Produces a sequence where “corresponding sensation” appears in the wrong place, breaking the phrase “there has to be a corresponding sensation”. - YZX or YXZ: Beginning with “kind, there has to be a …” after “If there is a” creates a confusing fragment and destroys the logical progression of the sentence.

Common Pitfalls:
Students sometimes pick an order that seems close in meaning but fails in grammar. In complex sentences, always ensure that connectors like “If there is a” are followed by a complete and logical clause, and that modifiers like “of a certain kind” are attached to the correct noun phrase. Also pay attention to where phrases like “there has to be a” must appear to introduce the result of the condition.

Final Answer:
The most logical and grammatically correct order is ZYX.