4. A vaccine used against an infectious disease may contain a. weakened pathogens
b. specialized blood cells
c. a variety of antibiotics
d. toxic enzymes
Help fast please

I believe the answer is A, weakens pathogens. this is because when you get a vaccine the purpose of it is for your body to fight it and build an immunity to the disease, so the vaccine contains weakened strands of the pathogen so that your body can fight it but not kill itself in the process.

C. a mature ovule of a plant.