Correct Answer: CREATE

Solution : Given:
UNNECESSARILY

Now, let's compare all the option words with the word UNNECESSARILY –
First option: RAINY; All the letters of RAINY are present in the word UNNECESSARILY.
Second option: CRANE; All the letters of CRANE are present in the word UNNECESSARILY.
Third option: LUNAR; All the letters of LUNAR are present in the word UNNECESSARILY.
Fourth option: CREATE; T is not present in the word UNNECESSARILY. Therefore, all the letters of CREATE are not present in the word UNNECESSARILY.

So, from the above, only CREATE cannot be formed using the letters of the word UNNECESSARILY. Hence, the fourth option is correct.