According to the Big Bang theory of the origin of the Universe, the age of the Universe is estimated at about :

According to the Big Bang theory, the universe originated from a singularity and has been expanding ever since. Modern cosmological measurements, primarily from the Planck mission (European Space Agency) and the Wilkinson Microwave Anisotropy Probe (WMAP), estimate the age of the universe to be approximately 13.8 billion years. In various scientific and academic contexts, this is often represented within the range of 13 to 15 or 13 to 18 billion years.

• Option B (4-6 billion years): This range corresponds to the age of the Earth and the Solar System (approximately 4.54 billion years).
• Option A (0.3 million years): This refers to the time after the Big Bang (around 380,000 years) when the universe cooled enough for atoms to form, known as the era of recombination.