When Young Male White-Crowned Sparrows First Begin to Sing, They

When young male white-crowned sparrows first begin to sing, they match their vocal output to ____.

A) any birdsong they hear during their initial days of singing
B) an instinctive blueprint of their species' song
C) the memory of their species' song heard months earlier
D) the memory of whatever song they heard during an early critical period
E) the songs of male relatives heard during their initial days of singing