Answer:
I believe the answer is d
I remember back in 10th grade I learned that birds that had beaks that were easier to break the seeds carried those traits to their babies and the whole area had that type of beak since it was necessary to break some seeds. So the beaks that were a disadvantage no longer existed and the beaks that became an advantage passed along to all the other birds.
Side note: if they all had the same beak they could all fight for the same type of seeds and probably have some sort of intense competition but idk if that’s necessary
Larger
During the process of breathing, the diaphragm contract by moving
downward and upward and this process usually increase or decrease the space in
the chest cavity. However, intercostal muscles between the ribs also help to enlarge
the chest cavity or reduce the space in the chest cavity.
The process of microsporogenesis