The correct answer is: Only conclusion II follows.
The statement says that the government has decided to withdraw 33% of the subsidy on cooking gas. This does not necessarily mean that people no longer desire or need such subsidy. It is possible that the government has decided to withdraw the subsidy in order to reduce the budget deficit, or to encourage people to use less cooking gas.
However, the statement does imply that the price of cooking gas will increase at least by 33% from the next month. This is because the subsidy is a form of government support that helps to keep the price of cooking gas low. When the subsidy is withdrawn, the price of cooking gas will naturally increase.
Therefore, only conclusion II follows.