Which two statements are true when upgrading Salesforce B2B Commerce from Release A to Release B? Choose 2 answers

Which two statements are true when upgrading Salesforce B2B Commerce from Release A to Release B? Choose 2 answers
A . Take a backup of all your Salesforce B2B Commerce data, since all data is most likely to get erased during the upgrade.
B. Salesforce B2B Commerce upgrades do not touch data in Salesforce B2B Commerce objects
C. Salesforce B2B Commerce upgrades ONLY replaces and adds to Managed Package Meta Data already installed.
D. Take a backup of all the Salesforce B2B Commerce extensions, since most likely all the extensions are going to be overwritten.

Answer: B,C