According to paragraph 4, white-crowns with which of the following life histories demonstrate the importance of memory in song acqusition A. White-crowns that learn a dialect before they learn their standard song B. White-crowns that first heard a dialect of the white-crown song before they were ten days old C. White-crowns that were moved from where they were born to a different region during their sensitive period D. White-crowns that were raised in nature through part of their sensitive period and then transferred to the laboratory