What is the most extendable way to update the Apex Trigger to accomplish this?

An Apex Trigger creates a Contract record every time an Opportunity record is marked as Closed and Won. This trigger is working great, except (due to a recent acquisition) historical Opportunity records need to be loaded into the Salesforce instance. When a test batch of records are loaded, the Apex Trigger creates Contract records. A developer is tasked with preventing Contract records from being created when mass loading the Opportunities, but the daily users still need to have the Contract records created .

What is the most extendable way to update the Apex Trigger to accomplish this?
A . Use a Hierarchy Custom Setting to disable the Trigger for the user who does the data loading.
B . Add a Validation Rule to the Contract to prevent Contract creation by the user who does the data loading.
C . Use a List Custom Setting to disable the Trigger for the user who does the data loading.
D . add the Profile Id of the user who does the data loading to the Trigger so the Trigger won’t fire for this user.

Answer: A