Explain how the Zhou discretionary family trust with the following particulars could distribute residual income to minimize tax at the end of the 2021 income year, given the following:

• Taxable income of $60,000 at the end of the income year.
• A choice of three beneficiaries, all of whom could be made presently entitled to a portion of the income and are a resident of Australia for tax purposes:
  1. Fred who is 45 and has other taxable income of $28,000.
  2. Samantha who is 20 and has no other income.
  3. Beth who is 16 and has no other income.

When answering the question please consider relevant marginal rates and tax offsets.