Answer: b. the cosmological principle.
Now we are talking more About Cosmological Theory.
The observations so far support the idea that the universe is both isotropic and homogeneous. Both facts must be done according to cosmological principles. Cosmological theories are derived from Copernican theories, but have no basis in any physical model or theory, that is, they cannot be "determined" in the mathematical sense. However, this is supported by many observations of our universe and is more important than a clear empirical basis.
The fact that the laws of physics are universal is consistent with cosmological theory. The same physical rules and models on Earth operate in distant stars, galaxies, and all parts of the universe - greatly simplifying our research. It should be noted that physical movements (a constant continuum of confidence, mass of electrons, speed of light) also do not change from place to place with the universe and time.
The most obvious modern evidence of cosmological theory is the measurement of cosmic microwave background. CMB is an image of photons emitted from the first universe. Isotopes and homosexuality are reflected in their random form.
The great result of the cosmological theory is that all parts of the universe have been linked in the past without any reason (although they are no longer connected). Thus, a homogeneous universe concludes that the entire universe exists simultaneously, a creation.
Finally, we extend the cosmological theory to the theory of the universe, that the universe is isotropic and cohesive and that there is a 'perfect' cosmological theory that always exists. This means that the laws of nature do not change, and it can be assumed that what we have seen in the past works under similar physical conditions in physics.