Critical Reasoning — Implicit Assumptions Statement: Traffic jams on most city roads have become a regular feature during monsoon. Assumptions: I. Material used for road construction cannot withstand monsoon, causing innumerable potholes. II. The number of vehicles on roads is much higher in monsoon than in other seasons.

Introduction / Context:
The statement notes a seasonal pattern: frequent traffic jams during monsoon. We must identify which causal belief is being assumed to explain this recurrence.

Given Data / Assumptions:

• Observation: jams are regular in monsoon.
• Assumption I: poor road durability in rains leads to potholes and congestion.
• Assumption II: traffic volume increases in monsoon vs other seasons.

Concept / Approach:
When a statement highlights a seasonal recurrence, typical implicit causes relate to seasonal conditions (rain damage, waterlogging) rather than to counter-seasonal spikes in vehicle count. Monsoon-damaged surfaces slowing traffic is a standard underpinning assumption.

Step-by-Step Solution:

Verification / Alternative check:
Negate I: roads withstand monsoon perfectly — then jams would require a different explanation; the highlighted seasonal regularity loses a natural cause. Negate II: vehicle numbers do not increase — the statement can still be true due to worse road conditions. Thus only I is needed.

Why Other Options Are Wrong:

• Only II, Either, Both, or Neither: They either introduce an unnecessary condition or ignore the plausible monsoon-specific cause tied to infrastructure.

Common Pitfalls:
Assuming every repeated event must be due to demand spikes. Supply-side constraints (road quality) can be the critical seasonal factor.

Final Answer:
Only assumption I is implicit