Final answer:
In vehicles, a convex rear-view mirror provides a clean, unobstructed view of the highway to the rear but can make objects appear smaller and further away.
Step-by-step explanation:
The mirror that is located to reflect to the operator a clean, unobstructed view of the highway to the rear is typically a rear-view mirror that uses diverging, also known as convex, mirrors. Convex mirrors are favored in vehicles because they provide a wider field of view compared to flat mirrors, which allows for an unobstructed and comprehensive view of the highway behind. However, a main disadvantage of using a convex (diverging) mirror is that objects in the mirror may appear smaller and further away than they actually are, potentially making it difficult for the driver to judge the distance of vehicles behind them accurately.