Answer
The supply of land is perfectly inelastic in nature. Taxes implemented on inputs discourage the uses of such resources. He supported the idea that the government could earn enough revenue by simply taxing the land. Taxing land today is not the only source of government income, it is not sufficient enough.
Work Step by Step
This question asks you to think about land based on elasticity then apply it to modern times to understand the fact that a simple tax on land is not enough revenue for government expenditures.