What is the age of universe according to Big Bang theory ? A) 10.8 billion years B) 13.8 billion years C) 15 billion years D) None of these Related MCQs: According to Big Bang theory concepts, the universe is? According to the Big Bang Theory, the Universe began about billion years ago? Big Bang theory was proposed in 1920 by? The echo of Big Bang theory can be heard in the form of?