W g of benzoic acid is completely burnt in bomb calorimeter in excess of $O_2$  so that Q KJ heat is released at 298K. Internal energy change for combustion of 1 mole benzoic acid (molecular weight = M) will be (in KJ)

When W g of of benzoic acid is completely burnt in bomb calorimeter in excess of ${\mathrm{O}}_2$ then the amount of heat released is Q KJ.

Now this heat will be in negative because the heat is released by the system, i.e., -Q KJ.

1 mole of benzoic acid will be equal Molecular weight  (M).

So, the internal energy will be:

$\frac{(-\mathrm{QM})}{\mathrm{W}}$ 

Therefore, the correct option is C.