Why should a passenger vehicle driver check mirrors immediately before signaling a lane change, not just after?

Pick an answer

1. Checking beforehand is only a habit some drivers prefer, without a real safety reason, similar to adjusting the radio before a shift
2. To confirm no standing passenger is in a position that a sudden lane-change movement could throw off balance
3. It's mainly to make sure the mirror itself hasn't come loose
4. It only matters for checking the vehicle's own blind spot, not the passengers

Correct!

Not quite. The correct answer is highlighted.