Contiguous : Abut — Select the pair that mirrors the relation “adjacent in contact” ↔ “to touch at a boundary”.

Introduction / Context:
Here the first word is an adjective and the second is a verb describing what such things do. “Contiguous” means sharing a common border; “to abut” describes touching or meeting at a boundary. We must find a similar adjective → verb pairing that preserves definitional alignment.

Given Data / Assumptions:

• contiguous → abut (adjacent; to touch).
• We need another adjective whose defining property is captured by the verb in the pair.

Concept / Approach:
“Simultaneous” (occurring at the same time) aligns with the verb “coincide” (to occur together in time). This mirrors the definitional fit seen in the stem. Other options either mismatch part-of-speech roles or break definition linkage.

Step-by-Step Solution:
Match definition: adjective’s property → verb describing that property.Simultaneous → Coincide matches time co-occurrence.Select that pair.

Verification / Alternative check:
Dictionaries: simultaneous = existing/occurring at the same time; coincide = occur at the same time/place.

Why Other Options Are Wrong:

• Possible : Occur — “possible” doesn’t entail that it occurs.
• Synthetic : Create — incorrect direction (create → synthetic product).
• Constant : Stabilise — not definitional; stabilise is an action, not constant’s necessary verb.
• Parallel : Converge — opposite behaviors.

Common Pitfalls:
Choosing near-domain words without strict definitional mirroring.

Final Answer:
Simultaneous : Coincide