Step 1: Understanding the Concept:
The question asks for the common characteristic among Folketing, Storting, and Knesset.
Step 2: Detailed Explanation:
Folketing is the Parliament of Denmark, Storting is the Parliament of Norway, and Knesset is the Parliament of Israel. All are names of national parliaments.
Step 3: Final Answer:
Therefore, the correct option is (C) They are the name of Parliaments.