Statement: There has been a remarkable increase in air traffic in India during the past few years.\nAssumptions:\nI. Air travel has now become a status symbol.\nII. A large number of people are now able to afford air travel.

Introduction / Context:
The statement notes a sustained, remarkable rise in air traffic volume. We must identify which assumption is necessary to reasonably explain the increase without adding extraneous claims about social signaling or prestige.

Given Data / Assumptions:

• Observed fact: air traffic has grown strongly.
• No explicit mention of status, branding, or cultural aspiration.
• India-specific context; affordability and access have been changing.

Concept / Approach:
For an assumption to be implicit, it should be a required underpinning of the inference from fact to explanation or recommendation. We ask: what must be true for increased traffic to be plausible nationwide?

Step-by-Step Solution:
1) If more people can afford air travel (II), rising traffic is naturally explained: price reductions, income growth, competition, and connectivity expand demand.2) The "status symbol" claim (I) may sometimes influence choices but is not necessary. Traffic could rise due to lowered fares, more routes, or business expansion without any prestige-driven motive.3) The observation itself neither mentions nor relies on social-status dynamics.

Verification / Alternative check:
Even if air travel is not a status symbol, affordability and availability alone can still cause large increases in passengers. Therefore I is not required, while II provides a necessary, general explanation.

Why Other Options Are Wrong:

• Only I: Prestige is not required to explain growth.
• Either / Both: I is not necessary.
• Neither: II is plausibly necessary to undergird nationwide growth.

Common Pitfalls:
Confusing possible causes with necessary assumptions. A trend can be explained by affordability without invoking status.

Final Answer:
Only assumption II is implicit.