When the organization-wide default (OWD) is set to Private, baseline access to records is restricted to the record owner and users above them in the role hierarchy. The scenario requires granting a VP access to records owned by individuals in "various parts of the role hierarchy," which implies access is needed beyond what the standard vertical role hierarchy provides (e.g., across different branches). Sharing Rules are the appropriate mechanism to grant this type of access. They create automatic exceptions to the OWD, extending record visibility to specified groups or roles based on record ownership or criteria, thus solving the VP's reporting requirement.

A. Field-Level Security: This controls user access to specific fields on a record, not access to the record itself. It assumes the user can already see the record.

C. Permission Sets: These grant users additional permissions and settings, such as object-level access (Create, Read, Edit, Delete), but do not grant access to specific records based on ownership criteria.

D. Restriction Rules: These are used to reduce the set of records a user can see. They apply a filter to the records a user already has access to, rather than granting new access.

1. Salesforce Help, "Sharing Rules": "Sharing rules give particular users greater access by making automatic exceptions to your org-wide sharing settings. Use sharing rules to extend sharing access to users in public groups, roles, or territories." This document explicitly states that sharing rules are used to grant wider access when OWDs are restrictive.

2. Salesforce Help, "Control Who Sees What" Trailhead Module, "Organization-Wide Defaults" Unit: "After you specify org-wide defaults, you can use a role hierarchy, sharing rules, and manual sharing to open up access to records for users who don't own them." This places sharing rules as a primary tool for extending access beyond the OWD and role hierarchy.

3. Salesforce Security Guide, "Managing the Sharing Model," Page 21: "Sharing rules represent the exceptions to your organization-wide default settings... For example, if you have an organization-wide default of Public Read-Only or Private, you can define rules that give users access to records they don’t own." This directly supports using sharing rules to solve the problem described.

4. Salesforce Help, "Restriction Rules": "Restriction rules prevent users from accessing records that contain sensitive data or information that isn’t essential to their work. Restriction rules filter the records that a user has access to..." This confirms that restriction rules reduce, not grant, access.