Final answer:
Europeans chose slaves from Africa in the New World due to a shortage of indigenous people caused by warfare and diseases.
Step-by-step explanation:
One reason Europeans chose slaves from Africa as a labor source in the New World is because indigenous people were in short supply due to warfare and diseases. The native populations in the Americas had been greatly reduced by diseases brought by Europeans, such as smallpox. This created a need for a new labor force, which the Europeans found in enslaved Africans.
Learn more about Reasons for the use of African slaves in the New World