The correct response is:
Both the focus and the epicenter occur at the origin of the earthquake. The focus refers to the very center of where the waves originated. The epicenter refers to the location on the surface directly over the focus.
To clarify:
- The focus (or hypocenter) is the point within the Earth where an earthquake originates, specifically the location where the fault begins to rupture.
- The epicenter is the point on the Earth's surface that is directly above the focus and is typically where the most severe damage is recorded during an earthquake.
This response accurately distinguishes between the two concepts.