Which one of the followings belongs to Exceptions in term of enterprise content management when we analyze the business work flow?

Question $7$Select one:

a$.$

A transitory document is deprecated automatically after $3$ months

b$.$

The manager cannot retrieve all the emails regarding to a customer$$s complain.

c$.$

The invoice sent to a customer has a wrong balance.

d$.$

The company has released version $1\mathrm{.}5$ of an official document, but the change or update of the document from version $1\mathrm{.}1$ to version $1\mathrm{.}2$ cannot be found.