Among the Yanomami of Brazil and Venezuela, It Is Considered

Among the Yanomami of Brazil and Venezuela, it is considered proper to have sexual relations with one's opposite-sex cousins if they are the children of one's mother's brother or father's sister. But it is considered incest if one's opposite-sex cousins are which of the following?

A) The children of one's mother's mother or father's father.
B) The children of one's mother's sister or father's sister.
C) The children of one's mother's brother or father's brother.
D) The children of one's mother's sister or father's brother.