Which tax applies to all capital gains made by UK residents?

Capital Gains Tax is the correct answer because it specifically applies to the profit made from selling assets, such as stocks, property, or other investments, by individuals who are resident in the UK. When a UK resident sells an asset for more than its purchase price, the gains are subject to this specific tax.

Capital Gains Tax is distinct from Income Tax, which pertains to earnings from employment or other income sources, and Corporate Tax, which applies to the profits of companies rather than individuals. National Insurance, on the other hand, is a form of tax on earnings that fund specific benefits and is not related to capital gains.

Thus, only Capital Gains Tax encompasses all gains made by UK residents from asset sales, making it the relevant tax for the situation described.