A comet's tail: a. always lies in the ecliptic plane, because a comet is a part of the Solar System.
b. lies between the comet and the nearest planet, because of gravitational attraction.
c. lies between the comet and the Sun, because the gravitational attraction of the Sun dominates over planets.
d. always trails along the orbital path, because of the comet's motion.
e. always points away from the comet in the anti-Sun direction because of the solar wind and light pressure.