Final goods or services used to compute GDP refer to:

the sum of all wages paid to laborers.

the factors of production used to produce output.

goods and services purchased by the ultimate users.

the value of outstanding shares of stock of manufacturing firms.

The correct answer is letter "C": goods and services purchased by the ultimate users.

Explanation:

The Gross Domestic Product (GDP) measures a country's performance over a period. GDP is calculated by adding private consumption, government expenses, investments, and net exports (exports minus imports). While calculating the GDP, final goods and services are those end-consumers acquired, those that will not be sold again, or used for production during the period computed.