Final answer:
The tax law certification level necessary for a tax preparer depends on the complexity of the tax return; however, an advanced level is typically better for complex situations. Labor supply decisions are influenced by the marginal tax rate, and a tax cut does not always lead to increased tax revenues according to the Laffer curve.
The correct option is 4.
Step-by-step explanation:
When Mary assigns the return to a tax preparer, the level of tax law certification the tax preparer should have depends on the complexity of the tax return.
However, if we are referring to the certification levels within the IRS's Annual Filing Season Program or similar tax law certification frameworks, typically, a preparer with an Advanced certification level is more knowledgeable and able to handle complex tax situations compared to someone with just a Basic level.
Nevertheless, for straightforward tax returns, a preparer with a Basic certification may suffice. Without more context on the complexity of Mary's return, it's not possible to definitively specify the level required.
Addressing the Self Check Questions, labor supply decisions are more affected by the marginal tax rate rather than the average tax rate because it influences the additional income earned from extra work. In relation to the Laffer curve, it suggests that there is an optimal tax rate that maximizes revenue and that a tax cut does not always increase tax revenues; it depends on where the current tax rate sits in relation to this optimal point.
The correct option is 4.