Question

when we see a meteor shower it means that
you should duck & run for cover to avoid being hit on the head by a rock from space
earth is crossing the orbit of a comet
an earth - approaching asteroid has recently come very close to our planet

Explanation:

Meteor showers occur when Earth crosses the orbit of a comet. Comets leave behind trails of debris, and when Earth passes through these debris - filled regions, the particles burn up in the atmosphere, creating the appearance of a meteor shower. It is highly unlikely for a large enough rock to hit a person during a meteor shower. An Earth - approaching asteroid coming close doesn't directly cause a meteor shower.

Answer:

Earth is crossing the orbit of a comet