A problem detector system produces an alarm in the factory when one of the three conditions occurs. The system is designed as such tha only one condition can occur at a time. If the three conditions are defined as q, r, and s respectively, the output logic for the system is given as

• A. q̅rs + r̅ s̅
• B. qr̅ s̅ + q̅sr̅ + q̅rs̅
• C. qrs̅ + r̅
• D. q + r + s