A User Has Setup a Billing Alarm Using CloudWatch for $200

A user has setup a billing alarm using CloudWatch for $200. The usage of AWS exceeded $200 after some days. The user wants to increase the limit from $200 to $400? What should the user do?

A) Create a new alarm of $400 and link it with the first alarm
B) It is not possible to modify the alarm once it has crossed the usage limit
C) Update the alarm to set the limit at $400 instead of $200
D) Create a new alarm for the additional $200 amount