In the analogy “Wax : grease :: Milk : ____”, which option best represents a similar product derived from milk?

Introduction / Context:
This analogy connects substances with related products that share similar properties. Wax and grease are both oily, semi solid materials used for lubrication or protection. The pair “Wax : grease” suggests a relation based on consistency and function. To complete “Milk : ____”, you must identify a product of milk that has a comparable relationship to milk as grease has to wax, emphasising the transformation into a fatty, thicker substance.

Given Data / Assumptions:

• First pair: Wax and grease.
• Second pair: Milk and an unknown product.
• Options: protein, drink, ghee, curd, calcium.
• We consider typical milk products used in daily life.

Concept / Approach:
Wax and grease are both substances with an oily nature. Grease is often made from fats and oils and is thicker than many liquids. Similarly, ghee is a clarified form of butter that is rich in fat and has a thick, oily consistency derived from milk. Curd is also made from milk but is more watery and sour, and the other options are not specific milk products. The closest parallel to the way grease relates to wax is the way ghee relates to milk as a fatty derivative.

Step-by-Step Solution:

Step 1: Consider the first pair. Wax is a solid or semi solid substance, and grease is a thick oily substance often made from fats and waxy materials. Step 2: Understand the relationship as moving from a base substance to a more oily, fatty derived substance used for lubrication. Step 3: For the second pair, start from milk, which contains fats that can be processed into richer products. Step 4: Ghee is obtained from butter, which in turn comes from milk fat, and it is a thick, oily substance used for cooking, similar in feel to grease compared to other liquids. Step 5: Compare ghee with other options and see that it best matches the idea of a fatty derivative of milk.

Verification / Alternative check:
Check the alternatives carefully. Protein is a nutrient found in many foods, not a specific product like grease. Drink is a general term that can include milk but does not denote a derived substance. Curd is a milk product but it is more of a semi solid with a sour taste and is not analogous to grease in texture and use. Calcium is a mineral present in milk but again is not a direct thick, oily product. Ghee is clearly recognised as a fat based product from milk and matches grease in its role and consistency.

Why Other Options Are Wrong:
Protein and calcium are components of milk, not distinct consumable products in the sense used in the analogy. Drink is too broad and does not represent a transformation of milk. Curd, although derived from milk, is not primarily used as a fat or lubricant and does not share the same greasy character that ghee and grease share. Therefore, none of these options capture the intended parallel as effectively as ghee does.

Common Pitfalls:
Some students may pick curd because it is a very common milk product, without considering the qualitative similarity of the pairs. Others might be misled by nutritional thinking and choose protein or calcium. In analogies, it is important not only to find any connection but to match the type of relation, such as base substance to oily derivative, across both pairs.

Final Answer:
The best completion of the analogy is that milk is to ghee as wax is to grease.