Correct Answer:
A. Karachi
Explanation:
The correct answer is Karachi because its coastal position and massive deep-water sea ports make it the primary entry point for international trade into the country.
- Step 1 (Economic Hub): As Pakistan's largest city and financial capital, Karachi handles the vast majority of the nation's maritime trade through the Port of Karachi and Port Qasim.
- Step 2 (The Title): Because it connects inland industries with global shipping lines and hosts the country's busiest international airport, it is traditionally called the Gateway of Pakistan.
- Incorrect Options:
- Peshawar is historically called the 'Gateway to Central Asia' due to its proximity to the Khyber Pass, but not the gateway city of Pakistan itself.
- Lahore is famous as the cultural heart of the country.
- Islamabad is the modern administrative capital city.