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.