Answer:
Option (A)
Step-by-step explanation:
A key is a commonly used feature that is often shown in a rectangular box, comprised of different symbols with different colors and lines, representing a particular feature. It is used to provide the reader the information regarding any particular place, as it makes convenient for map reading. These symbols are used to highlight the important places such as the roadways, railway tracks, hospitals and schools, and all these features are shown by distinct and particular symbols. This key is also known as legends.
Thus, the correct answer is option (A).