Having no beginning or end to its existence

A. Eternal

B. Obscure

C. Universal

D. Immeasurable

Answer: Option A

Solution(By Examveda Team)

One word substitute is Eternal.

Eternal: lasting or existing forever; without end.
Obscure: not discovered or known about; uncertain.
Universal: relating to or done by all people or things in the world or in a particular group; applicable to all cases.
Immeasurable: too large, extensive, or extreme to measure.