Correct Answer: CONTRACT

Solution : Given:
COMMENTATOR

Now, let's compare all the option words with the word COMMENTATOR –
First option: MART; All the letters of the word MART are present in the word COMMENTATOR.
Second option: COMMON; All the letters of the word COMMON are present in the word COMMENTATOR.
Third option: MOMENT; All the letters of the word MOMENT are present in the word COMMENTATOR.
Fourth option: CONTRACT; All the letters of the word CONTRACT are not present in the word COMMENTATOR. The word COMMENTATOR has only one C but in the word CONTRACT two C are present.

Therefore, CONTRACT cannot be formed from the word COMMENTATOR. Hence, the fourth option is correct.