The relative number of atoms of different elements in a compound are as follows. $A=1.33, B=1$ and $C=1.5$. The empirical formula of the compound is

The ratio of number of atoms of A,B and C = $1.33:1:1.5$

Simplifying it we get the ratio for A,B and C= $8:6:9$

Empirical formula is the simplest way in which a compound can be represented.

Hence in this case the empirical formula of compound will be- $A_8{B}_6{C}_9$.

Hence option C is the correct answer.