Final answer:
The correct answer is C6 and C7 as they are integral in anchoring the membrane-attack complex to the targeted cell membrane.
Step-by-step explanation:
The membrane-attack complex (MAC) is a ring structure formed from complement proteins C5 through C9 that penetrates the membranes of a targeted cell, causing cell lysis and death. Components C6 and C7 are particularly important in anchoring the MAC to the membrane it is targeting. Thus, the correct answer to which components are important in anchoring the MAC to the membrane is C6 and C7, meaning option c. C6 and C7 is the correct choice.