Step 1: Understanding the Concept:
The question asks for the common characteristic among Irna, PTI, and Xin-Era.
Step 2: Detailed Explanation:
Irna (Islamic Republic News Agency) is Iran's news agency, PTI (Press Trust of India) is India's news agency, and Xin-Era is China's news agency. All are national news agencies.
Step 3: Final Answer:
Hence, the correct option is (C) They are news agencies.