Robert Is in His Early Sixties and Is Annoyed That

Robert is in his early sixties and is annoyed that he takes longer to remember the names of his grandchildren and the dates of their birthdays than it did when he was fifty. According to information processing theory, what should Robert be told?

A) "This sort of change in this time frame is an indication of memory disorders to come."
B) "While not a major concern at this point, it is important to keep up with activities like crossword puzzles."
C) "Practice at memory retrieval strategies will increase your processing speeds."
D) "This is natural as you have accumulated so many memories and knowledge, that it takes longer to retrieve relevant items.