Which of the following is a type of evidence supporting the Big Bang theory?

• A. Red shift
• B. Solar eclipse timing
• C. Planetary orbits
• D. Stellar parallax

Answer: (A)

Redshift as evidence for the expanding universe is what this item focuses on. Distant galaxies emit light with spectral lines shifted toward longer wavelengths. That Doppler shift means those galaxies are moving away from us. The greater the shift, the faster the recession, and observations show a clear trend: more distant galaxies recede faster. This universal expansion is exactly what the Big Bang theory predicts, that the cosmos began in a hot, dense state and has been expanding over time.

The other options don’t address the history of cosmic expansion. Solar eclipse timing is about when eclipses occur due to the relative positions of Sun, Moon, and Earth, not about the universe’s origin. Planetary orbits describe motion within the solar system under gravity. Stellar parallax measures distances to nearby stars, which relates to local scales rather than the expansion of the universe.