Answer:
I pick embryo similarities.
Explanation:
Vertebrates have a resemblance of their embryos. Such as birds, amphibians, fish, reptiles and mammals. Though there's resemblance but it doesn't form the same organism since there's evolution which might be due to geographic and ecological isolations.
Example, Amphibian embryo resemble with fish embryo.
Robert hooke discovered small compartments that he called cells
I think the answer would be c. because for birds with longer beaks, it was easier to eat seeds off a cactus (for example), and for birds with shorter seeds, it was easier to eat seeds off the ground.
The two natural resources that will be most affected as people try to meet the growing demand for food are the use of land and water.
I think the answer you are looking for is oxidative phosphorylation! :)