The UA5000 V100R019 supports continuous upgrades and internal database upgrades.What are the steps of upgrade? (Multiple Choice)

The UA5000 V100R019 supports continuous upgrades and internal database upgrades.What are the steps of upgrade? (Multiple Choice)
A . Export old database files
B . Upgrade to a new version of the database file
C . Restart the device
D . Load the upgrade package

Answer: CD