Work authorization system based communication

[suresi00]

Rosemary is the project manager at a pharmaceutical company. She begins her day by analyzing her team's work requirements. She then
assigns daily tasks to her team members over a centralized project management information system that generates task assignment
notifications for the team members. Which of the following types of communication methods has been selected by Rosemary?
A. Formal, push communication
B. Informal, pull communication
C. Formal, pull communication
D. Informal, push communication"

I agree with push communication , I cannot agree to the explanation saying it is informal because it was email.

Manish sir where do you categorize this and why

[manishpn]

emails and memos are informal as per PMBOK page 287