what will AWS do?

A user has launched an RDS postgreSQL DB with AWS. The user did not specify the
maintenance window during creation. The user has configured RDS to update the DB instance
type from micro to large. If the user wants to have it during the maintenance window, what will
AWS do?

A.
AWS will not allow to update the DB until the maintenance window is configured

B.
AWS will select the default maintenance window if the user has not provided it

C.
AWS will ask the user to specify the maintenance window during the update

D.
It is not possible to change the DB size from micro to large with RDS

Explanation:
AWS RDS has a compulsory maintenance window which by default is 30 minutes. If the user does
not specify the maintenance window during the creation of RDS then AWS will select a 30-minute
maintenance window randomly from an 8-hour block of time per region. In this case, Amazon RDS
assigns a 30-minute maintenance window on a randomly selected day of the week.