The correct answer is: A) Hyderabad.
Hyderabad is the capital of Telangana and the sixth most populous city in India. It is a major center for Urdu language and culture. According to the 2011 census, 12.4% of the population of Hyderabad spoke Urdu as their first language. This is the highest percentage of Urdu speakers in any city in India.
Karimnagar is the second most populous district in Telangana. It is located in the northern part of the state. According to the 2011 census, 10.4% of the population of Karimnagar spoke Urdu as their first language.
Warangal is the third most populous district in Telangana. It is located in the central part of the state. According to the 2011 census, 9.2% of the population of Warangal spoke Urdu as their first language.
Nalgonda is the fourth most populous district in Telangana. It is located in the southern part of the state. According to the 2011 census, 8.4% of the population of Nalgonda spoke Urdu as their first language.
In conclusion, Hyderabad is the district in Telangana with the most significant Urdu-speaking population.