Answer: $\mathbf C$
Explanation:
Group the vowels together and make it a single packet $= \mathbf {OUE}$
Rest of the words are: $\mathbf {CMPTR}$
$\therefore$ Total words to be grouped including one packet $ = \mathbf {\underbrace{(OUE)}_\text{=3!}CMPTR} = 6!3!$
$\therefore$ Answer $ = \mathbf {3!6!}$
$\therefore \mathbf C$ is the correct option.