Which set of procedures will be required to perform a rolling upgrade in
a HADR environment?

A.
1. Upgrade the system where the primary database resides.
2. Issue the TAKEOVER HADR command on the primary database server.
3. Upgrade the original primary database.
4. Return to the original configuration by switching the roles of the
primary and standby databases

B.
1. Upgrade the system where the standby database resides.
2. Issue the TAKEOVER HADR command on the primary database server.
3. Upgrade the original primary database.
4. Return to the original configuration by switching the roles of the
primary and standby databases

C.
1. Upgrade the system where the primary database resides.
2. Issue the TAKEOVER HADR command on the primary database server.
3. Upgrade the new primary database.
4. Return to the original configuration by switching the roles of the
primary and standby databases

D.
1. Upgrade the system where the standby database resides.
2. Issue the TAKEOVER HADR command on the standby database server.
3. Upgrade the original primary database.
4. Return to the original configuration by switching the roles of the
primary and standby databases