Percentage of Oxygen = $100 - (40 + 6.67) = 53.33\%$. Calculate the relative number of atoms: $C = 40/12 = 3.33$, $H = 6.67/1 = 6.67$, $O = 53.33/16 = 3.33$. The simple whole number ratio $C:H:O$ is $1:2:1$. Thus, the empirical formula is $CH_2O$. Empirical formula mass = $12 + (2 \times 1) + 16 = 30$. To find the molecular formula, calculate $n = \text{Molar mass} / \text{Empirical formula mass} = 180 / 30 = 6$. Molecular formula = $n \times (\text{Empirical formula}) = 6 \times (CH_2O) = C_6H_{12}O_6$. Option 2 is the empirical formula, and Options 3 and 4 have incorrect molar masses ($60$ and $90$ respectively).