Answer:
Today most people in developed countries have a scarcity of food sources.
Edwin Hubble used the Doppler effect to determine that the universe is expanding. After years of scientific research and observation of different celestial bodies through a telescope, Hubble found that the light from distant galaxies was shifted towards the red end of the spectrum. This red shift indicates that stars are moving away from us and from each other. This phenomenon is called the 'expansion of the universe', also known as the big band theory.
I think that answer is they are like Opposite poles of magnet.
I really hope it’s right
B is the most efficient answer