Workaround is applied when an unknown (a previously UNidentified) risk occurs and you need to come up with a solution like immediately. You didn't plan for it, but it occurred and now you have to manage it. Contingency is for already (previously) identified risks.
Active acceptance is a high-level definition.
Here is a learning tool for you on CRS. Logically what is a work around? I feel a work around is the same or closely like a mitigation strategy that you put in place to remove the risk before it happens but after identified.
CRS I feel is the same as disaster recovery plan (DRP) in the event something happens this is my strategy to counter act it. Active acceptance? Well just as it says you know it is there, understand the consequences and "let it ride"
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