White blood cells migrate to a source of infection by amoeboid migration along the surfaces of endothelial cells. Imagine you have discovered a toxin that suppresses the immune system by specifically inhibiting pseudopod formation in white blood cells. Which of the following is your toxin's most likely mechanism of action? O It interferes with the interaction between actin monomers. O It prevents hydrolysis of GTP. O It causes Ca++ to leak out of the smooth ER. O It prevents ATP hydrolysis.