The complement system is:

a. a set of proteins involved in innate but not acquired immunity.
b. a set of proteins secreted by cytotoxic T cells and other CD8 cells.
c. a group of antimicrobial proteins that act together in a cascade fashion.
d. a group of proteins that includes interferons and interleukins.

a. a set of proteins involved in innate but not acquired immunity.

Explanation:

The complement system are a set of proteins or protein fragments that play a major role in the innate immune system. The complement system is involved in the defense of the body from foreign pathogen through specific plasma proteins that participate in leukocyte activation, chemotaxis and opsonization. In other words, they increase the ability of phagocytes and antibodies to mop up damaged cells and foreign microorganism, activate inflammation process.

Some of these proteins include complement component 3 (C3), complement component 9 (C9) and  C1Q complex.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.