Answer:
2 ways by couple
Step-by-step explanation:
firstly out of 4 wives 1 can enter boat and take other women 1 by 1 to other side..
after completing taking 3 wives by 1 wife, this women can take hes own husband with her to reach at other side, which other women will not be jealous of thier husband.
after reaching women with her husband and that men can go back to cary all gents to reach at other side.