Final answer:
The ecliptic is both the path of the Sun on the celestial sphere and the projection of Earth's orbit onto the celestial sphere, answering option E. It's inclined due to Earth's axial tilt and passes through the constellations of the zodiac.
Step-by-step explanation:
The ecliptic is defined as both the path of the Sun on the celestial sphere and the projection of Earth's orbit onto the celestial sphere. Therefore, the correct answer is E. Both B & C. The ecliptic is an important concept in astronomy as it represents the apparent path that the Sun follows over the course of a year against the backdrop of the celestial sphere. It is inclined by about 23.5° relative to the celestial equator, due to the tilt of Earth's axis.
The ecliptic passes through the zodiac constellations, which are a set of constellations that the Sun, Moon, and planets frequently traverse, owed to the alignment of their orbits within a comparable plane. This path is directly related to many astronomical phenomena, including the changing position of the Sun in the sky throughout the year, and is foundational for understanding the movement of celestial bodies as observed from Earth.