Final answer:
The correct answer is that when properly parked, no part of a vehicle extends into the traffic lane. This ensures safety and avoids potential traffic issues.
Step-by-step explanation:
When your vehicle is properly parked in a straight-in parking space, the correct answer is a) No part of your vehicle will extend out into the traffic lane. Vehicles that stick out into the traffic lane can pose a danger to other road users, potentially causing traffic disturbances or accidents. Therefore, it's important to ensure that the entire length and width of your vehicle is within the boundaries of the parking space. This is supported by the safety principle that you need to have enough distance to cross the road safely in front of oncoming cars, which are typically discussed in terms of car lengths.