In the context of the input sentence, determine the relationship between 'Boko Haram' and 'Abubakar Shekau'.
Options: publisher, chairperson, director/manager, product/material produced

Boko Haram has released a new video on the insurgency in Nigeria, with its leader Abubakar Shekau again failing to … see more » Copyright © 2015 Daily Trust.
chairperson