The statement that most accurately describes inequality in the U.S. is:
The median rural income is less than the median urban income.
This is a well-documented trend, with rural areas generally having lower median incomes compared to urban areas due to various economic factors.
The other statements about gender and ethnic income gaps, as well as comparisons with other countries, are more complex and may not be entirely accurate as they can vary depending on the measures used and the specific context in which they are examined.