Q 8 from chap6 of Manning book

[vijaya bacina]

which of the following is not a requirment of a distributable web-application(select one)
a)it cannot depend on notification events generated due to changes in Servletcontext attribute list
b) it cannot depend on notification events generated due to changes in Session attribute list
c)it cannot depend on notification events generated when session is activated or passivated
d)it cannot depend on notification events generated when servletcontext is created or destroyed
e)it cannot depend on notification events generated when Session is created or destroyed

answer given is c:
IS B incorrect???