It is Big Bang and cannot be proved. A hypotheses must be testable. Big Bang is not testable.
In the early stages the embryos of four different species will look the same .For example, fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth. That what makes them different.
A X-rays I think this is the answer
It's B. The cheetah populations are less likely to be able to adapt to environmental changes.
Answer:
Catalyzing Chemical Reactions
Explanation: