Classification — impurities/residue vs main item: pick the pair that is NOT “impurity/residue : main food/drink.”

Introduction / Context:
Three pairs name an unwanted impurity or leftover matched with a main commodity (food/drink). One pair instead names the desirable produce and its broader category (part→whole of the good itself).

Given Data / Assumptions:

• Chaff : Wheat → chaff is removed from wheat grain.
• Grit : Pulses → grit/pebbles are impurities removed from pulses.
• Dregs : Wine → sediment/residue in wine.
• Grain : Crop → grain is the harvested produce of a crop (not an impurity).

Concept / Approach:
Group by “impurity/residue vs main item.” The lone positive-produce relation is the odd one.

Step-by-Step Solution:

Verification / Alternative check:
During processing, chaff/grit/dregs are removed; grain is what we keep.

Why Other Options Are Wrong:
They consistently reflect “remove the unwanted from the wanted.”

Common Pitfalls:
Assuming any relation counts; the question targets impurity mapping.

Final Answer:
Grain : Crop