The description matches Casual Callers recruitment because:
1. Definition: - Unsolicited applications/walk-ins - Maintained in talent pools
2. Advantages: - Cost-effective (no agency fees) - Pre-screened candidates - Faster hiring for urgent needs
3. Industry Usage: - Common in retail, hospitality sectors - Tech companies maintain "cold applicant" databases
4. Distinction: - Not (A) Direct: Active solicitation (career fairs) - Not (C) Contractors: Third-party labor providers - Not (D) Campus: College recruitment programs
Final Answer: (B) Casual callers