Answer:
b. They are distantly related, so their development is similar.
Step-by-step explanation:
Chicken and cow belong to classes Aves and Mammalia of the phylum Chordata. The embryonic development of these two animals is the same. As a result the embryos of these two species looks similar during the earliest stages of embryonic development. The embryos of these organisms looks dissimilar after differentiation in the later stages of development. This explains ontogeny repeats phylogeny. Therefore, the early stages of embryonic development provide evidence of organic evolution. Thus, the chicken and cow is distantly related species.