Q6

[jdieck]

I ended up choosing B, which is now I see is unsupported by the passage. My reasoning was that the learning and relearning process is controlled by neurogenesis.

[maryadkins]

Good catch. While the songs is what led scientists to research the canaries, it isn't the theory of why they have adult neurogenesis. That is lifespan (A), which is supported by line 42.

The other answer choices make it about breeding and song-learning, but these aren't given as REASONS for the adult neurogenesis. Lifespan is.