Identify the word that CANNOT be formed using the letters of the word 'CELEBRATION'.

Let's inspect the available letters in 'CELEBRATION':
$\text{{C, E, L, E, B, R, A, T, I, O, N}}$
Now let's check Option C ($\text{SELECTION}$):
It contains the letter 'S'. Looking at the word 'CELEBRATION', there is no letter 'S' present anywhere. Therefore, the word $\text{SELECTION}$ cannot be formed.