The diagram shows the embryo development of four vertebrates and suggests all of the following except a) common ancestry of vertebrates. b) there are no similarities in the embryos of all four groups. c) there are very few differences in the early development of any vertebrates. d) common features (gills and segments) in the embryos of all vertebrates.

The correct answer would be B) there are no similarities in the embryos of all four groups.

There are similarities in various stages of the embryonic development of different species. They look very similar in the early stages of development. The ancestors of the different animals are same and this implies that they are related.  

For example, the embryo of both human and fish has gill slit but in the later stages, the gill slit of human embryo disappears. The difference in later stages shows the evolution of different traits but the beginning of creatures are same.

It is why comparative embryology is also used to provide evidence of evolution.

Thus, the development of four vertebrates and suggests all of the following EXCEPT there are no similarities in the embryos of all four groups.  

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.