Which of the following statements best describes the fiscal year for companies?

Multiple choice question.

Only public companies are allowed to set their fiscal years differently from the calendar year.

A fiscal year is a fixed period and cannot be changed once a company decides its start and end dates.

All companies must use the calendar year $($January $1$ to December $31)$ as their fiscal year.

Companies often choose a fiscal year that aligns with the natural cycle of their business, which may not coincide with the calendar year.