Which of the following represents lines of longitude?

The answer is indeed meridians, which are fundamentally important for geographic orientation. Meridians are the vertical lines that run from the North Pole to the South Pole, marking the positions of points east or west of the Prime Meridian. They provide a framework for measuring longitude and are crucial in navigation and mapping.

In contrast, parallels refer to lines of latitude, which run horizontally and measure how far north or south a location is from the Equator. The Equator itself is the primary line of latitude at 0 degrees, serving as the midpoint between the poles and indicating no north or south positional value. Circles, while they can represent various circular measurements in geometry, do not specifically denote geographical coordinates and are less specific in the context of mapping Earth’s surface. Thus, meridians are the correct representation of lines of longitude.