All of the options are types of taxes.

The ability-to-pay principle is the principle of taxation that states that taxes should be levied according to the ability to pay.

All of the options are international agreements that seek to prevent double taxation.

Tax evasion is not a type of international tax, but rather a crime.

The benefit principle is the principle of taxation that states that taxes should be levied on goods and services that are consumed.

A Free Trade Agreement (FTA) is not a type of tax treaty.

The equal treatment principle is the principle of taxation that states that taxes should be levied in a fair and equitable manner.

Double taxation is not a type of tax avoidance, but rather a situation where the same income or asset is taxed more than once.

The administrative feasibility principle is the principle of taxation that states that taxes should be easy to administer and collect.

Tax amnesty is not a type of tax incentive, but rather a program that allows taxpayers to pay back taxes without penalty.

The fiscal policy principle is the principle of taxation that states that taxes should be used to fund government spending.

Wealth is not a type of tax base, but rather a measure of economic well-being.

The uniformity principle is the principle of taxation that states that taxes should be levied on a uniform basis.

A flat tax rate is not a type of tax rate, but rather a tax rate that is the same for all taxpayers.

The timeliness principle is the principle of taxation that states that taxes should be levied on a timely basis.