Answer:
b. Because instant messaging is not a secure method of communication.
Step-by-step explanation:
Instant messaging (IM for short) allows communication between people in real time and it is internet based. By real time, it means, unlike emails where messages are downloaded from the server, which consumes considerable amount of time, IM allows for communication without so much delay.
While IM has many great advantages, one of its biggest disadvantages is security. IM is a third party application and as such it is vulnerable to malicious attacks, data can be stolen and the system can be intruded into.
Hope this helps!