Final answer:
Ben is most likely responding to Christopher when he says, 'Hey for coming back.'
Step-by-step explanation:
Based on the provided information, the question is asking who Ben is responding to when he says, 'Hey for coming back.' To answer this question, we need to analyze the conversation between Brayden and Christopher.
From Brayden's statement, we can infer that Christopher has been gone for some time and Brayden expected him to be gone permanently. Therefore, when Ben says, 'Hey for coming back,' he is likely responding to Christopher since Brayden expresses surprise at Christopher's return.
This conversation is based on social interactions and does not pertain to a specific subject or grade level.