Which of the following complement act as a chemoattractant of neutrophils?

C5a and the C5,6,7 complex attract neutrophils. They migrate especially well toward C5a. C5a also enhances the adhesiveness of neutrophils to the endothelium. Ref: Levinson W. (2012). Chapter 63. Complement. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.