Final answer:
An oil sample should be taken for reasons like routine maintenance and driving safety, particularly to understand the effect of oil on wet surfaces which can reduce friction and increase slipperiness.
Step-by-step explanation:
An oil sample should be taken for several reasons, such as routine maintenance, environmental monitoring, performance evaluation, and responding to accidental spills. However the context of the take-home experiment suggests a focus on the importance of understanding how substances like water and oil affect the friction between surfaces which is crucial for driving safety after rain showers.
The experiment illustrates how the addition of oil to a wet surface can reduce friction significantly, making it more slippery and more challenging to control motion. This can be critical for drivers following a light rain shower because roads become more slippery a condition that can lead to accidents if drivers are not cautious.