Which best explains why a population of a certain species of giant pacific octopus developed larger beaks than most octopus populations?

a. warming ocean waters led to only larger clams being around, requiring a larger beak to break through their shell
b. octopus with larger beaks were able to find more dns to sleep in than those with small beaks
c. only octopus with smaller beaks were able to survive and reproduce
d. oysters began disappearing from the ecosystem, leading to less food for the octopus