Table: list of doctor who audio plays by big finish
Question: What is the most common combination of characters featured in Big Finish audio plays?
Step 1 (Operation, Indexing): featuring
Step 2 (Reasoning, Grounding): combination of characters, the same two or three characters
Step 3 (Operation, Grouping): count of featuring combination of characters
Step 4 (Reasoning, Arithmetic): max, count of featuring combination of characters
Answer: tegan , nyssa