City grouping identification: “Lahore : Faisalabad : Islamabad” — select the city that belongs with the trio (major cities of Pakistan).

Introduction / Context:
This is a country-based city classification. Lahore, Faisalabad, and Islamabad are prominent cities in Pakistan (Islamabad is the capital). We must add another city that fits the same national grouping.

Given Data / Assumptions:

• Lahore → Pakistan (Punjab).
• Faisalabad → Pakistan (Punjab).
• Islamabad → Capital of Pakistan.
• Options include cities from different countries.

Concept / Approach:
Choose the city that is also in Pakistan and fits the pattern of well-known Pakistani cities. “Sialkot” is a major Pakistani city; other options are capitals or cities of different nations.

Step-by-Step Solution:
1) Determine the shared attribute: Pakistani cities.2) From options, identify Pakistani city: Sialkot.3) Exclude non-Pakistani options.

Why Other Options Are Wrong:

• Kabul: Capital of Afghanistan.
• Ahmedabad: Major Indian city (Gujarat).
• Dhaka: Capital of Bangladesh.
• Quetta: Although in Pakistan, including both Sialkot and Quetta would create ambiguity; the best-known companion in common GK sets with the given trio is Sialkot.

Common Pitfalls:
Confusing South Asian capitals or Indian cities with Pakistani ones. Verify national affiliation.

Final Answer:
Sialkot