Which of the following describes the difference between a Great Circle and a Rhumb Line on the Earth's surface?

1. A Great Circle is the shortest distance between two points but has a constantly changing track; a Rhumb Line crosses all meridians at a constant angle.
2. A Rhumb Line is the shortest distance between two points; a Great Circle is a line of constant heading.
3. A Great Circle is only found along the equator; all other lines on the Earth are Rhumb Lines.
4. A Rhumb Line represents magnetic headings; a Great Circle represents true headings.