How can this information can be entered and de-duplicated against existing individuals in the Nonprofit Success Pack (NPSP)?

A nonprofit organization uses a vendor for direct mail, and receives a monthly spreadsheet from it with donor information, donation amounts, and the solicitation campaign that the donation was in response to.

How can this information can be entered and de-duplicated against existing individuals in the Nonprofit Success Pack (NPSP)?
A . Use the Salesforce Data Loader to upload the spreadsheet and then manually check for duplicates and use the NPSP Contact Merge tool to de-duplicate records.
B . Upload the spreadsheet using the NPSP Data Importer and associate the individuals with Opportunities and Recurring Donations.
C . Use the Salesforce Import Wizard to upload the spreadsheet and then de-duplicate records using the NPSP Contact Merge tool.
D . Upload the spreadsheet using the NPSP Data Importer and associate the individuals with Opportunities and Campaigns.

Answer: D