Which ond is true about antigens a) a substance produced by white blood cells and that helps destroy pathogens

b) a disease causing microorganisms

c) a medication that helps treat bacterial infections

d) a protein on the surface of a cell that acts like an identification card

Explanation:

one characteristic that is shared by all is a soft body. many

of these invertebrate animals also have an outer shell to protect their

body. oysters, clams, snails, and mussels are all mollusks. so are octopuses, squids, and slugs. mollusks live on land and in freshwater.