What is the correct definition of an antigen? Please help

A. a dead pathogen introduced into the body to cause an immune response

B. a substance that sends the immune system into action

C. a protein to keep pathogens from harming the body

D. a white blood cell of the lymphatic system

Smoking cigarettes is a pervasive habit found in many parts of the world and a habit that could be explained by both microsociological and macrosociological forces. give an example of each that would be relevant to explaining the proliferation of smoking. how might your suggested micro- and macro-level analyses be linked

Explain one cultural view of relationships

Which plan groups foods according to types and indicates how much of each type should be eaten daily for a healthy diet? a. mypyramid plan b. food guide pyramid plan c. dietary guidelines for americans d. dietary pyramid guidelines