The correct answer is option (D):
celestial
The correct answer is celestial because it represents an antonym, or a word with an opposite meaning, to terrestrial.
Terrestrial means relating to the earth or to land. It refers to things found on Earth.
Celestial means relating to the sky or the heavens. It refers to things in space, like stars, planets, and the moon.
The other options, economical, ecclesiastical, and social, do not share this antonym relationship with terrestrial.