A. Free land was given to white heads of households over 21
The Headright System was a land grant program designed to attract settlers by giving each head of a household a certain amount of land for themselves and additional acreage for each person (i.e., family member or indentured servant) they transported to the colony. It was used in several colonies, including Virginia and Maryland, during the 17th century. Although option A is not completely precise in its description—it omits the key aspect that heads of households usually received land for transporting additional people to the colony—it is the closest to the actual Headright System among the options provided.