The system is a contributor to both innate and humoral immunity that requires sequential activation.

The correct answer is: The complement system.

Explanation:

-The complement system can also be known as the complement cascade is one of the fundamental components of the system that helps the organism defend from pathogen agents.

-It is known as the complement system because it helps antibodies in the task of clearing microbes and damaged cells, and attacking pathogen agents.

-The complement system is a part of the inmune system as is brought into action via activation of the adaptive inmune system.

In conclusion, the complement system is a contributor to both innate and humoral inmunity that requires sequential activation.

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