Word formation from letters of COMMUNICATION Which ONE of the following words cannot be formed from the letters of “COMMUNICATION”, using each letter at most once?

Introduction / Context:
We must find the single option that cannot be made from the source letters, respecting multiplicities.

Given Data / Assumptions:

• Source: COMMUNICATION ⇒ letters include C,O×2,M×2,U,N×2,I×2,A,T.
• Letter S does not occur in the source.

Concept / Approach:
Rules of multiset inclusion: every letter in the option must appear in the source with at least the required count.

Step-by-Step Solution:
“ACTION”, “UNION”, and “NATION” can be assembled from available letters.“UNISON” requires S, which is absent, so it cannot be formed.

Verification / Alternative check:
Quick letter scan confirms no S in COMMUNICATION.

Why Other Options Are Wrong:
They are constructible using the given multiset of letters.

Common Pitfalls:
Confusing similar-looking words and overlooking a missing consonant such as S.

Final Answer:
UNISON