Critical reasoning — assumptions (implicit): Statement: Kartik left for Delhi on Tuesday by train to attend a function to be held on Friday at his uncle's house in Delhi. Assumptions: I. Kartik may reach Delhi on Wednesday. II. Kartik may reach Delhi before Friday.

Introduction / Context:
The statement narrates travel plans: Kartik left on Tuesday by train to attend a Friday function in Delhi. We must identify what the speaker must assume for this plan to be sensible.

Given Data / Assumptions:

• Departure: Tuesday by train.
• Event: Friday in Delhi.
• Assumption I: Arrival specifically on Wednesday is possible.
• Assumption II: Arrival before Friday is possible.

Concept / Approach:
The core presumption is feasibility: that the travel schedule allows Kartik to be there before the Friday function (II). The precise day of arrival (Wednesday) is just one possibility among several and is not required by the plan.

Step-by-Step Solution:

Verification / Alternative check:
Negate II: If reaching before Friday were not possible, leaving Tuesday would not serve the stated purpose. Negate I: If Wednesday arrival were not possible but Thursday were, the plan still works. Hence II is required; I is not.

Why Other Options Are Wrong:

• Only I/Either/Neither/Both: These either elevate a nonessential detail (I) or miss the necessary feasibility assumption (II).

Common Pitfalls:
Confusing a concrete example timeline with a necessary condition. Plans rely on arriving in time, not on a particular intermediate date.

Final Answer:
Only assumption II is implicit