The answer is B because the humoral immune response is mediated by antibody
<span> d/ They create small currents in their microenvironment that help to circulate and clean water locally for other organisms.</span>
Contractile vacuoles are organelles that are responsible for excretion function. They perform osmoregulation which manages wastes, water and other needed materials in the cell. They are found in some prokaryoric organisms like the algae, protists, amoeba and other unicellular organisms.
