Final answer:
The counterargument statement in the discussion about school start times is that a later start time would be problematic for sports teams.
Step-by-step explanation:
The counterargument statement in the provided text is: d) True, a later start time would be a problem for sports teams. This statement acknowledges a potential negative consequence of implementing a later school start time, which counterbalances the argument that delaying the start of the school day to 9 A.M. will benefit students' learning abilities.