Question

Which part of map explains the symbols, colors, and lines?

A. Key
B. Scale bar
C. Compass rose
D. Inset

Answer 1

The key would be your best bet at the answer or A.

As the Key is the part of maps that explain what lines, colors, or other indicators mean. It gives a quick couple of words on what it is to represent; a secondary word for it would be "legend."

Example

Solid Line ( In a Key) May mean the border between two states or countries.

Answer 2

The key tells you what everything is. Also commonly known as a 'legend'.