There Is a correlation between the Timing of the Addition

Multiple Choice

There is a correlation between the timing of the addition of new neurons to the affected song center and the song learning sequence in male zebra finches. This leads us to conclude that

A) both of these events must be caused by some outside variable.
B) song learning causes the addition of new neurons.
C) the nature of the relationship needs to be tested experimentally.
D) the new neurons cause song learning to take place.