For me answer is C, using the elimination process technique A - Normal change "for review" B - Emergency change "critical software patch" C - Standard change "normall this is pre-approved" D - Emergency change "major incident"

C. A standard change is a type of change that is pre-authorized and routine, with a well-defined process for execution that has a low level of risk and has been approved in advance. It is typically used for changes that are repetitive, low impact, and have been proven to be successful through experience.

5.2.4 Change enablement Standard changes: These are low-risk, pre-authorized changes that are well understood and fully documented, and can be implemented without needing additional authorization. They are often initiated as service requests, but may also be operational changes. When the procedure for a standard change is created or modified, there should be a full risk assessment and authorization as for any other change. This risk assessment does not need to be repeated each time the standard change is implemented; it only needs to be done if there is a modification to the way it is carried out.

I have been working on many CHGs over the years ... 'B' mentined the "critical" so it means an Emergency change -> as soon as possible in case of 'D' I guess a Normal change would be fine -> if you make any change you need a nornal CHG an should be approved on the CAB. in 'A' two phase of the change workflow mentined about the Change Management lifecycle so only 'C' remains, but would notice that application installation allowed only if it's on the "green list" and it's widely used in your organization.

5.2.16 Service request management - Fulfilment of service requests may include changes to services or their components; usually these are standard changes