How do supporting details reinforce the central idea in this passage?

“The month of February gets its name from ancient Rome. In Latin, the
language of Rome, februum means "cleansing." Originally, the month
was named after a Roman cleansing ritual that took place during the
winter. Later, this word was translated into English as February. The
month of February has had 28 days (or, in a leap year, 29) for more”
than 2,000 years.

A. The supporting details show why February has 28 days.

B. The supporting details explain why the Roman cleansing ritual
affected the number of days in February

C. The supporting details help the reader understand how February
got its name.

D. The supporting details give examples of why Roman months were