Answer:
Option-A
Step-by-step explanation:
The Africans were brought into America by the Britishers in 1619 as indentured servants. Later the Blacks were brought as enslaves for their lifetime and heredity servitude was established as legal action in 1640.
The suitable type of soil and the climatic conditions of the South led to the plantation of the indigo, tobacco and rice in South. The increased plantation of the tobacco demanded labour due to which the import of Blacks as slaves increased between 1650 to 1750.
The tobacco plantation and the increased labour is the main reason for the increase in the population of the Blacks between 1650 to 1760.
Thus, Option-A is the correct answer.