The following are true about the Fc regions of an immunoglobulins:
a. they can be cleaved from the Fab regions by papain
b. they are involved in mast cell binding
c. they are involved in the activation of the complement cascade
d. all above
a. they can be cleaved from the Fab regions by papain
b. they are involved in mast cell binding
c. they are involved in the activation of the complement cascade
d. all above