[单项选择]

An enormous variety of relationships between men and women, singly and in groups, meet the definition of marriage. Often the forms of marriage sanctioned by a society are related to the needs of that society. Marriage between two individuals, one male and one female, is known as monogamy. Marriage of three or more individuals is known as polygamy.
Polygyny is a form of polygamy in which one male is married to more than one female. Polyandry is a form of polygamy in which one female is married to more than one male. Still another form of polygamy is group marriage, in which two or more males are married to two or more females. In some societies a polyandrous marriage of two men with one woman may become a group marriage through the addition of a second woman. Not uncommonly in these marriages, the co-husbands are brothers and the added woman is the first wife’s sister.
In general, polygyny presupposes a considerable accumulation of wealth and is therefore rar
A. Since women between 13 to 45 are eager to find husbands, sometimes they have to marry married men because of the shortage of unmarried men.
B. Sex ratio and money greatly influenced the probability of conducting polygamy.
C. Polygamy can only be practiced by the older and wealthier men.
D. Wealthy men are old men.