Final answer:
A religious act or ceremony through which God's grace is received is known as a C)sacrament, a term particularly important in Christian traditions.
Step-by-step explanation:
A religious act or ceremony through which God's grace is received is called a C) sacrament. The term 'sacrament' represents not only a religious rite but is also specifically tied to the experience of receiving God's grace as understood within various religious contexts, particularly in Christianity.
For instance, in Christian traditions, ceremonies such as Baptism, Communion, and Confirmation are considered sacraments because they are outward signs of inward grace. Moreover, the sacraments were largely administered by the clergy, and their role in spiritual life was significant, being seen as essential to salvation.