Analyze the relationship between 'Boko Haram' and 'Abubakar Shekau' within the context of the input sentence.
Options: chairperson, industry, business division, publisher

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