The correct answer is option (D):
Earthly
The correct answer is "Earthly." The word "celestial" refers to anything relating to the heavens or outer space. It often implies a sense of divinity, perfection, or being beyond the realm of human experience. The antonym, therefore, needs to represent the opposite – something related to the Earth, the physical world, and human existence.
Let's look at why the other options are incorrect:
* "Sacred" is a synonym of celestial, suggesting a holy or divine nature.
* "Hazardous" implies danger or risk, a concept that is not directly related to the concept of being "celestial."
* "Unhealthy" refers to a state of poor health and doesn't represent the opposite of "celestial."
* "Glorious" implies splendor and magnificence. While it could be associated with celestial things, it's not the direct opposite.
"Earthly" directly contrasts "celestial" by referring to the physical world, the ground, and human life. It represents the opposite domain in which "celestial" is understood.