A basement is defined as any area of the building, including any sunken room or sunken portion of a room, having its floor below ground level (subgrade) on all sides.

FEMA IS-200.B: ICS for Single Resources and Initial Action Incidents Answers

Here are the FEMA IS-200.B: ICS for Single Resources and Initial Action Incidents Answers

Here are the IS-1102: Theory of Elevation Rating Course Answers