which detail would be most relevant to the central idea?

George Washington’s presidency still has an impact on our government today.

1. George Washington was elected on unanimously.
2. George Washington created the two term policy for president.
3. George Washington was the first president.
4. George Washington married Martha Custis.

The most relevant detail to the central idea would be option 3 - George Washington was the first president. This detail directly relates to the central idea of George Washington's presidency having an impact on our government today.