Firuz Tughlaq, also known as Firoz Shah Tughlaq, was the third ruler of the Tughlaq dynasty in India. He reigned from 1351 to 1388. During his reign, Firuz Tughlaq founded several cities across northern India, aiming to establish his authority and leave a lasting legacy. Among these cities are:

1. Jaunpur:
Jaunpur is a city in the state of Uttar Pradesh, India. It was founded by Firuz Tughlaq in 1359. The city served as an important center of Islamic culture and scholarship during the Tughlaq period.

2. Hissar:
Hissar, also known as Hisar, is a city in present-day Haryana, India. Firuz Tughlaq founded this city in 1354. Hissar was strategically located and served as an important administrative and military center during the Tughlaq rule.

3. Firuzpur:
Firuzpur, also spelled Ferozepur, is a city in the state of Punjab, India. It was founded by Firuz Tughlaq in 1360. The city played a significant role in the history of Punjab and served as an important trading and military center.

4. Firuzabad:
Firuzabad, also known as Firozabad, is a city in the state of Uttar Pradesh, India. It was founded by Firuz Tughlaq in 1354. The city was intended to serve as the capital of Firuz Tughlaq's empire but was later abandoned.

All of the above:
Therefore, the correct answer is option 'E' - All of the above. Firuz Tughlaq founded Jaunpur, Hissar, Firuzpur, and Firuzabad during his reign as the ruler of the Tughlaq dynasty. These cities were established for various purposes, including administration, military control, and cultural development. They played important roles in the history and heritage of the regions they are located in.