Omniscient : Knowledge — Pick the pair that preserves the “all-/complete-” quality applied to a domain.

Introduction / Context:
“Omniscient” means all-knowing; it ascribes an all-encompassing quality to the domain of knowledge. We must find a pair where the first word denotes an “unlimited/complete” quality fitting the second word’s domain.

Given Data / Assumptions:

• Omniscient applies a totalizing quality to knowledge.
• We need an adjective applying an analogous totalizing quality to its noun.

Concept / Approach:
“Boundless : Expanse” captures an unbounded/limitless quality applied to a spatial domain (expanse). This parallels “omniscient : knowledge.” Other pairs mismatch tone or logic.

Step-by-Step Solution:
Identify: adjective denoting vast totality → appropriate noun domain.Map: boundless → expanse (limitless extent).Select that pair.

Verification / Alternative check:
Thesaurus mapping supports boundless ≈ limitless; expanse is a wide, continuous area.

Why Other Options Are Wrong:

• Saturnine : Energy — saturnine = gloomy; misfit with “energy.”
• Inquisitive : Science — inquisitive describes a person, not the domain.
• Complete : Retraction — semantic mismatch.
• Frugal : Wealth — not a totalizing quality of wealth.

Common Pitfalls:
Picking any positive adjective; ensure the adjective’s meaning applies naturally to the noun.

Final Answer:
Boundless : Expanse