A systems application servers need to be

patched. The requirements for maintenance work are as follows:

System downtime is not allowed.

The application server in use must be in the sane patch status.

System performance must be maintained during patching work.

Testing after patching must be done

before the application server is in use.

If any trouble occurs, recover the previous version in ten minutes.

Which of the following methodologies should be selected?

A. Rolling update

B. Patching directly

C. Blue-green deployment

D. Three staging enviro

nments