In this classification question, each option shows a pair of related words: Flower : Petal, Circle : Arc, Cover : Page, Chair : Leg. Three of the pairs show the same kind of relationship between whole and part. Which pair is different from the other three responses?

Introduction / Context:
This is an analogy-based classification question. Each option gives a pair of related words. Your task is to identify which pair does not share the same type of relationship as the others. These items test whether you can see that three pairs present a clear whole–part relationship, while one pair is different because both words in that pair represent parts of another whole rather than a whole and its part.

Given Data / Assumptions:
• The given pairs are: Flower : Petal, Circle : Arc, Cover : Page, Chair : Leg (and an extra illustrative pair Book : Chapter).• Three pairs must show a consistent relation.• One pair must break that pattern.• We use standard meanings of the words in English.

Concept / Approach:
Look at each pair in terms of whole versus part. A petal is part of a flower. An arc is part of a circle. A leg is part of a chair. In each of these, the first term is the whole object and the second term is a physical portion of that whole. But in the pair Cover : Page, neither word is the whole object. Both cover and page are parts of a larger whole, namely a book or a notebook. Therefore, this pair does not follow the same whole–part pattern and must be the odd one out.

Step-by-Step Solution:
Step 1: Analyse Flower : Petal. A petal is one of the units that form a flower; it is clearly a part of the whole flower.Step 2: Analyse Circle : Arc. An arc is a segment or a portion of a circle; again, it is a part of the whole geometric figure.Step 3: Analyse Chair : Leg. A leg is one of the parts that supports a chair; a typical chair has multiple legs, each being part of the whole structure.Step 4: In all three, the pattern is Whole : Part.Step 5: Now analyse Cover : Page. A cover is part of a book (or notebook), and a page is also part of a book.Step 6: Here, both words represent parts of some third object (a book); neither is a whole that contains the other as a part.Step 7: Therefore Cover : Page does not share the same whole–part pattern as the other three pairs.

Verification / Alternative check:
Another way to check is to ask: can the second item exist as a natural component of the first? A petal is literally part of a flower, an arc is an identified piece of a circle, and a leg is a structural component of a chair. However, a page is not a component of a cover; both are placed together in a book, but one is not part of the other. This contrast confirms that Cover : Page is different from the rest.

Why Other Options Are Wrong:
Flower : Petal: Correctly shows a whole–part relation.Circle : Arc: Again, a clear whole–part relationship.Chair : Leg: The leg is a part of the chair structure.Book : Chapter (if considered): The chapter is part of the book, aligning with the whole–part pattern.

Common Pitfalls:
Some candidates get distracted by the idea that cover and page belong to the same domain (both parts of a book) and mistakenly treat them as having a meaningful relationship. While they are associated, the relationship is not the same whole–part type that appears in the other pairs. To find the odd one out, always look for which pair breaks the shared underlying relation, not just which words seem less related at first glance.

Final Answer:
The pair that is different from the others is Cover : Page.