Bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
The underscore.
But actually you can use spaces in file names, in many file managers. I think it just shows you a space while it actually saves an underscore, or something like this.
Answer:
CUI will be classified at a “moderate” confidentiality level and follow DoDI 8500.01 and 8510.01 in all DOD systems. Non-DoD systems must provide adequate security with requirements incorporated into all legal documents with non-DoD entities following DoDI 8582.01 guideline
Explanation:
The answer would be B because ".edu" stands for education and it shows there was a source for the information