Explanation:

- Say’s Law of Markets: It asserts that supply creates its own demand. This principle is crucial to classical economics, suggesting that everything produced will ultimately find a buyer.

- Flexibility in Wage Rates: Classical theory assumes wages adjust to equate labor supply and demand. This flexibility helps maintain employment equilibrium.

- Flexibility in Interest Rates: Interest rates are seen as self-regulating, equalizing saving and investment, ensuring all resources are employed.

- All of the above: Classical economics relies on all these assumptions for its models of full employment and economic balance.