From Process of Elimination
A) It is Not Liquidity, since it does not effect Current Assets /Non-Current Assets.
B) Gearing is your Debt To Equity. Goods + Services Tax will not effect your debt to Equity, since you aren't funding anything.
C) Stability - >.> Not even in the syllabus.
D) Profitability - GST means an Increase of Expenses. and Since a Businesses Net profit is (Gross Income - Operating Expenses). If Expenses increase, then Net profit will decrease.