Answer:
The correct answer is -
8. They played the songs of medium ground finches and cactus finches through a loudspeaker at different times, when individuals from both species were present, to see which species responded to each song.
9. Males only came to the loudspeaker when the song of their own species was being played.
Step-by-step explanation:
To test the hypothesis that differences in finches song they sing keep these finches to breeding from other members of finches, Grant should play the different songs of both medium ground finches and cactus finches one by one in loudspeaker and see what members of finches respond on what song.
It will show that cactus fiches breed only on their songs and medium ground finches on their song if the hypothesis is true. Male of each species respond to their songs only and not on other song played on loudspeaker