Find the odd city (country): Identify the city that is not in India.

Introduction / Context:
Geographic classification by country borders offers a crisp filter. Three listed cities are in India; one is in a neighboring country, making it the clear outlier.

Given Data / Assumptions:

• Kanpur: India (Uttar Pradesh).
• Lucknow: India (capital of Uttar Pradesh).
• Patna: India (capital of Bihar).
• Lahore: Pakistan (Punjab province).

Concept / Approach:
Check national affiliation of each city. The mismatch in country immediately determines the odd item.

Step-by-Step Solution:

Verification / Alternative check:
State-capital check: Lucknow and Patna are capitals; Kanpur is a major Indian city; Lahore does not belong to India.

Why Other Options Are Wrong:
They are Indian cities and thus coherent as a set.

Common Pitfalls:
Similarity in cultural or historical heritage does not change modern national borders.

Final Answer:
Lahore