The data for species B supports hypothesis (1) since the capture rate is uniformly low of species B, indicating some problem for the bats in finding these moths, not learning to avoid them. The data for species A supports hypothesis (2) since the bats seem to learn over time to avoid these moths—perhaps the bats came to associate the clicks with the unpalatability of these bats. Only naive bats would be useful since bats used to tiger moths could have biases for or against one or the other species of prey (for example, they might have learned to circumvent jamming clicks).
Work Step by Step
To get this answer, review the data in the figure shown, and use your imagination to see which curve(s) might represent learning (decline in capture) versus jamming (uniformly low capture).