Correct Answer: PAVEMENT

Solution : Given:
PRONOUNCEMENT

Now, let's compare all the option words with the word PRONOUNCEMENT –
First option: MOUNT; All the letters of MOUNT are present in the word PRONOUNCEMENT.
Second option: CEMENT; All the letters of CEMENT are present in the word PRONOUNCEMENT.
Third option: PAVEMENT; All the letters of PAVEMENT are not present in the word PRONOUNCEMENT. A and V are not present in the word PRONOUNCEMENT.
Fourth option: NOUN; All the letters of NOUN are present in the word PRONOUNCEMENT.

So, from the above, only PAVEMENT cannot be formed using the letters of the word PRONOUNCEMENT. Hence, the third option is correct.