Which of the following helps explain the gains from trade liberalisation to the Australian economy:

A. As efficiency improves in the economy, returns to capital decline so firms increase investment and productive capacity.

B. As imports become cheaper, the numbers of unemployed increase because Australia can import goods and services rather than making them itself. Hence, costs are saved and Australia is better off.

C. By removing trade barriers employment can increase in more efficient sectors of the economy.

D. When import barriers such as quotas and tariffs are removed, imports that are used as inputs become more expensive meaning that exports can increase.