The most common marital system in the majority of preindustrial societies around the world is

a. neolocality.

c. polygamy.

b. matrilocality.

d. monogamy.

In the preindustrial societies it is/was common for men to fight each other for the goods, which results/resulted in the smaller number of men (when compared to the number of women). For this and other reasons it was typical for men to have multiple partners of wives - so the answer is polygamy!