The big bang theory was supported by the discovery of the
a- galaxies in the universe
b- temperature of the universe
c-gravitational forever between planets
d- red shift in electromagnetic spectrum

Option D, red shift in electromagnetic spectrum

Explanation:

According to the Big Bang theory the universe is continuously expanding and all celestial bodies are moving away from each other. This fact was established when red shift affect was discovered. A red shift is basically a shift/increase in the wavelength of light released by any star over a period of time. The farther the star, the more is its wavelength red shifted.

This red shift is continuously increasing which means that the light emitting celestial objects are continuously moving away from each other.

Hence, option D is correct answer

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.