Answer:
An immune response is a reaction which occurs within an organism for the purpose of defending against foreign invaders. The first contact that an organism has with a particular antigen will result in the production of effector T and B cells which are activated cells that defend against the pathogen.
Explanation:
A because it’s dna fragments
Syphilis is transmitted through sexual actions through small cuts, for malaria, it would have to be through mixing of blood from a contaminated source to a uncontaminated source.
