Which type of respiratory protection is preferable for repair/investigation personnel on a MODU in a hydrogen sulfide (H2S) environment?

Correct Answer: Option B — Pressure-Demand Self-Contained Breathing Apparatus (SCBA)

Pressure-demand Self-Contained Breathing Apparatus (SCBA) maintain positive pressure inside the facepiece, preventing toxic hydrogen sulfide (H2S) ingress and providing optimal respiratory protection during emergency investigations.