Real life example of scientist investigation using observation, hypothesis, and prediction

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods. c. it shows that these organisms share the same habitat. d. it provides evidence that these organisms suffered a genetic mutation.

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.