Tobacco : Cancer — Choose the option that expresses the same cause–effect relationship as in the given pair.

Introduction / Context:
Many analogies test recognition of cause–effect. “Tobacco : Cancer” captures a well-documented causal risk (tobacco use increases the risk of cancer). We must select the option that mirrors a similarly direct and widely acknowledged cause–effect linkage.

Given Data / Assumptions:

• Tobacco exposure is a known causal risk factor for cancer.
• The parallel should show an agent or vector causing a specific disease or effect.
• Only one option forms a clear cause–effect pair, not merely association or part–whole.

Concept / Approach:
Evaluate each option for causal direction: an agent or vector that typically leads to a particular outcome. Public health knowledge identifies mosquitoes as the vector for malaria transmission, forming a clean cause–effect structure akin to tobacco leading to cancer risk.

Step-by-Step Solution:
1) Identify “cause” (tobacco) and “effect” (cancer) in the stem.2) Test each option for the same pattern.3) “Mosquito : Malaria” expresses a vector-disease causal relationship.4) Other options are part–whole or process–product, not cause–effect.

Verification / Alternative check:
Public health literature consistently treats mosquitoes as the malaria vector; this is a standard textbook analogy comparable to “smoking : lung cancer risk.”

Why Other Options Are Wrong:

• Milk : Food: Category membership (milk is a food), not cause–effect.
• Bud : Flower: Developmental sequence, not pathology cause.
• Soil : Erosion: Erosion affects soil; direction and agency do not match the stem’s style.

Common Pitfalls:
Confusing correlation, sequence, or category with causation. The best answer clearly expresses an etiologic relationship.

Final Answer:
Mosquito : Malaria