Final answer:
Purchasing new production equipment like auto-making robots counts towards a country's GDP, as it is part of business investment and contributes to economic activity.
Step-by-step explanation:
Out of the options provided, ford C. buys new auto-making robots would be counted towards a country's GDP. Gross Domestic Product (GDP) is a measure of all the goods and services produced within a country's borders within a specific time period.
Purchasing new production equipment, such as auto-making robots, represents business investment and contributes to the country's economic activity. This type of transaction counts towards the calculation of GDP because it involves the production of new goods. On the other hand, a car mechanic repairing his own car or a social security check given to a retired man would not be included in GDP calculations as these are non-market transactions and transfers respectively.