Answer: B amy and sophie were born in the same calendar year; d sophie's mother is amy's aunt
Explanation: The amount of time between the beginning of the first day of January and the end of the last day of December in the Gregorian calendar is regarded as a calendar year. If Amy and Sophie are both nine, it then means they were born in any of the months of the same calendar year. Also, that they are friends doesn't drive the conclusion that they must be of the same age.
Sophie's mother could also be Amy's aunt if they're born of sister's of a family and vice versa. What this entails is that Amy and Sophie are cousins.