Who Were Known as the "Red-Headed Ones

Who were known as the "Red-headed ones?"

A) The Safavid Shi'a Imams, who donned red skull caps to signify reverence to God
B) The Sunni Turkish tribal forces who began the Safavid Empire's first military conquests
C) Followers of the Sufi Sunni brotherhood founded in Azerbaijan
D) They were both Turkish tribal forces and followers of the Sufi Sunni brotherhood founded in Azerbaijan