How does Earth’s position relative to the Sun cause the four seasons?

a. Earth orbits the Sun once a year and is in a different position with respect to the Sun every three months, resulting in four seasons.

b. The tilt of Earth’s axis with respect to its orbit changes back and forth approximately 46 degrees every six months, resulting in four seasons.

c. Earth’s axis is tilted with respect to its orbit, so, as it revolves around the Sun its tilt with respect to the Sun changes, resulting in four seasons.

d. Earth rotates on its axis every twenty-four hours, and, since the axis is tilted with respect to the Sun, different parts of Earth experience different day-lengths, resulting in four seasons