How do you do this?

A merchant is trying to improve the customer experience for register customer and needs to provide shipping tracking numbers.

How do you do this?
A . Tracking numbers can be entered during invoicecreation and they will only be visible after the order paid.
B . Tracking numbers have to be entered during shipping creation and they will be accessible in the Orders section in My Account immediately.
C . Tracking numbers are only supported for UPS, USPS and FedEX carries out-of-the box for other carries it will require it customization.
D . Tracking numbers can only be added to order comments via the admin

Answer: B