Which feature primarily distinguishes a meteor from a meteoroid?

The distinguishing feature that separates a meteor from a meteoroid is primarily related to size and atmospheric entry. A meteoroid is defined as a small rocky or metallic body in outer space, typically smaller than an asteroid. When a meteoroid enters the Earth’s atmosphere, it begins to burn up due to friction with the air, creating a bright streak of light known as a meteor. This translational change from meteoroid to meteor occurs upon atmospheric entry, where the interaction with air causes heating and visibility, which is a critical aspect of their difference.

While other options like location, composition, and orbital characteristics may provide additional context about celestial objects, they do not capture the essential transformation that defines when a meteoroid becomes a meteor during atmospheric entry.