Complete the dual analogy: “A : Winter :: B : Malaria”. Pick A and B so that each second term is countered or managed by the first (protective/treatment relation).

Introduction / Context:
The relation required is “problem/condition : customary countermeasure.” In winter, people use quilts to keep warm; for malaria, quinine (historically) and related antimalarials are treatments.

Given Data / Assumptions:

• Winter → quilt (protective warmth).
• Malaria → quinine (classical treatment).
• Countermeasure/control relation must hold on both sides.

Concept / Approach:
Choose items that directly mitigate the condition: quilts mitigate cold exposure; quinine treats malaria physiologically.

Step-by-Step Solution:
1) Map winter to a common protective item: quilt.2) Map malaria to a direct treatment: quinine.3) Verify symmetry: both are countermeasures.

Verification / Alternative check:
Wool is material, not the typical named item; “mosquito” is a vector, not a treatment. “Epidemic” and “fever” are states/effects, not countermeasures.

Why Other Options Are Wrong:

• Cold/Epidemic: Not countermeasures.
• Cold/Mosquito: Vector, not treatment.
• Wool/Fever: Material and symptom; not paired countermeasures.
• Heater/Vaccine: Vaccine is for prevention, not specific historical treatment context; also “heater” does not mirror “quilt” specificity.

Common Pitfalls:
Picking related objects (wool) or epidemiological terms (epidemic) instead of direct countermeasures.

Final Answer:
A. Quilt, B. Quinine