Choose the option that expresses the same causal relationship as “Tobacco : Cancer.”

Introduction / Context:
The stem “Tobacco : Cancer” is a textbook example of a cause → effect/public-health association (risk factor leading to disease). We must choose another pair that mirrors this causal disease-relationship pattern.

Given Data / Assumptions:

• Tobacco use is a major cause/risk factor for cancer.
• We need a vector/agent leading to a disease outcome.
• Distractors may show class-membership, part–whole, or non-causal relations.

Concept / Approach:
“Mosquito : Malaria” fits the causal mapping because mosquitoes transmit the malaria parasite to humans, resulting in the disease. This is parallel to “tobacco leads to cancer,” both being standard public health causation pairs taught in GK/Reasoning.

Step-by-Step Solution:
Identify relation type: cause/risk → disease effect.Find an equivalent: mosquito (vector) → malaria (disease).Select that pair.

Verification / Alternative check:
Epidemiology classifies mosquitoes as vectors for malaria, dengue, etc. The relation matches tobacco–cancer in causal direction.

Why Other Options Are Wrong:

• Milk : Food: Category relation (milk is a food), not cause–effect.
• Bud : Flower: Developmental sequence, not causation.
• Soil : Erosion: Environment and process; erosion is caused by water/wind, not soil itself.
• Accident : Injury: Often effect → effect, not a unique causal agent akin to tobacco or vectors.

Common Pitfalls:
Confusing correlation or category with direct causation. Pick a clear vector/disease pair.

Final Answer:
Mosquito : Malaria