There are two answers to this. The first one is A which is to change the record type of the record. The second answer is C. This is to apply a certain value to the field. A workflow field can be easily updated depending on your specifications. If you are not too familiar with what a workflow is in general, this places all of the actions that need to be done in sequence so that a goal can be achieved.
Through this, new tasks can be assigned to users and alerts can also be updated once again depending on your specifications. There are some workflow rules that should be considered to ensure that everything is smooth sailing.