The polarity of alcohol molecules decreases as size of the . increase or decrease

The polarity of alcohol molecule decreases as size of the molecule INCREASES.
The polarity of alcohol refers to the manner in which chemical bonds in alcoholic compounds results in unequal sharing of electrons. In polar compounds, the shared electrons is closer to one of the atoms in the bond than the the other and this lead to creation of  areas of positive and negative charges.
For alcohol, as the as the size of the molecule increases, the polarity decreases.

The gas would begin to expand, and eventually the can would burst or explode.

The answer is the first option just took the test