race currently earns $$35,000$ which means her marginal income tax rate is at lowest rate of $16\%$ plus $2\%$ Medicare Levy.

Which of the folloiwng would increase her after tax income the most?

If Grace received $$1000$ of extra taxable income

If the tax free threshold increased by $$1000$

All of these $($except none of these$)$

None of these

If a new rule was introduced allowing Grace to exclude $$1000$ from her taxable income