Nyinba women in Nepal and Tibet may have more than one husband simultaneously, which allows for: sons to share the usable land they inherit. more diversity in child reproduction. enforcement of the social norm prohibiting infidelity among wives. All of these answers are correct.

sons to share the usable land they inherit.

Explanation:

Nyinba in Nepal

They often have a form of marriage called the  fraternal polyandry. Sometimes, some brothers can divorce and turn monogamous.  there is a form of virilocal and patrilineal kinship that is wives marry all brothers in household

. The economy of the nyinba's is mostly farming, herding, long distance trade and a system  that is facilitated by marriage practices.

They are known to have lots of influence on china and india where also they have a rugged territories  usually isolated by mountains, isolated, not a lot of outside contacts, culture unchanging, generation to generation.

Marriage of  sororal (sisters) polygynous polyandry is also practiced.

Polyandry

This is also a form of birth control, it is where 1 women can marry many husbands. in Nyinba,  wife must  treat all husbands equal to preserve family

Nyinba women in Nepal and Tibet may have more than one husband simultaneously, which allows for sons to share the usable land they inherit.

the right answer is a

answer; broad features of society;