Stygian : Dark — Choose the pair with the same synonymy (rare/advanced adjective → common synonym).

Introduction / Context:
Verbal analogies often pair a higher-register adjective with its common synonym. “Stygian” means extremely dark or gloomy; thus the pair reflects synonymy. We must select the option where the first adjective has “almost the same meaning” as the second, not an antonym or unrelated term.

Given Data / Assumptions:

• Stygian ≈ very dark.
• We need an equivalently synonymic relation.
• Distractors may be antonyms or mismatches.

Concept / Approach:
“Fortuitous” means happening by chance; “accidental” is a close, common synonym conveying the same core sense. The other options pair words that are not synonymous (some are oppositional or unrelated).

Step-by-Step Solution:
Identify stem relation: rare adjective → common synonym.Scan options for true synonymy.Select “Fortuitous : Accidental.”

Verification / Alternative check:
Standard dictionaries list fortuitous ≈ accidental (though sometimes with nuance about chance vs. good fortune; the core sense of “by chance” matches).

Why Other Options Are Wrong:

• Abysmal : Low — “abysmal” means extremely bad; not “low.”
• Cogent : Contentious — cogent is convincing; contentious is argumentative (near-opposition of tone).
• Cataclysmic : Doomed — not synonyms; one is event-character, the other fate.
• Benign : Harsh — antonyms.

Common Pitfalls:
Confusing connotation with denotation; focus on core meaning equivalence.

Final Answer:
Fortuitous : Accidental