The correct answer is "Controlling diagnostic ports on networked equipment". This is an example of a hardware control.
The other three are examples of software controls.

Here are some examples of MTD values suggested by Shon Harris:
NonEssential 30 Days
Normal 7 Days
Important 72 Hours
Urgent 24 Hours
Critical Minutes to hours
The following answers were all incorrect:
Important Urgent Vital
The following reference(s) were/was used to create this question: Chapter 9: Business Continuity and Disaster Recovery CISSP Certification All-in-One Exam Guide, 4th Edition, Shon Harris

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Configuration control is controlling changes
to the configuration items and issuing versions of configuration items
from the software library.
Answer "Identifying and documenting the functional and physical characteristics of each configuration item" is the definition of configuration identification.
Answer "Recording the processing of changes" is the definition of configuration status accounting, and answer "Controlling the quality of the configuration management procedures" is the definition of configuration audit.