Answer:
The value of his work contributes to U.S. GDP when he works in the Alabama plant.
Explanation:
Gross domestic product is a measure of all goods and services that is produced domestically in a country, it does not involve foreign production that is achieved by a countrie's national.
So in this scenario Leo was working in Mercedes Benz factory in Alabama he was then moved to the South African factory.
His work will contribute to US GDP only when he worked at Alabama. His work in South Africa will contribute to South African GDP.