In NPSP, soft credits are fundamentally based on the Opportunity Contact Role (OCR) object. Even if "Partial Soft Credits" are used for splitting a gift, the primary mechanism for attributing a "Solicitor" to a donation is assigning them a specific role on the Opportunity.

Reporting Logic:

The Junction: The Opportunity Contact Role acts as the bridge between the Opportunity (the donation) and the Contact (the solicitor).

Standard Report Type: The standard report type Opportunities with Contact Roles allows the user to see the donor (the Account) and all related contacts who have a role on that gift.

Filtering: The Admin can filter this report by the "Role" field (e.g., Role EQUALS Solicitor). This surfaces exactly who the solicitor was for every donor's transaction.

Why other options are incorrect:

Option D: Partial Soft Credits is a more complex object used when multiple people get different dollar amounts of credit for a single gift. For a standard report showing "who the solicitor is," the Contact Role is the simpler and more standard starting point.

Option A: Relationships track person-to-person ties (like "Spouse" or "Coworker"), not who influenced a specific financial transaction.

Option B: This focuses on the Household structure rather than the individual donation influence history.