Answer:
b) a stickleback's aggressive behavior
Step-by-step explanation:
Sticklebacks are small carnivores that live off of small animals and larvae. An adapted behaviour would be changes in their attitudes and behaviours as compared to the characteristics are given to them by the Creator.
For example lions nature is to hunt, spiders nature is to build nests whereas birds nature is to build nests. But being aggressive is not one of Sticklebacks natural instincts. This is something they have adapted with time due to external factors.