Which statement best explains the significance of 1 January 1901 in relation to the Australian colonies?

Which statement best explains the significance of 1 January 1901 in relation to the Australian colonies?

• AIt was the date the Australian colonies became one independent nation, the Commonwealth of Australia.Correct
• BIt was the date the Australian colonies first became separate from each other.
• CIt was the date the Commonwealth of Australia became a group of colonies.
• DIt was the date Australia stopped being known as the Commonwealth of Australia.

According to the fact, 1 January 1901 is significant because the Australian colonies became one independent nation called the Commonwealth of Australia.