On a MODU, if there is a probability of encountering H2S during the drilling of a well, where should the air movers (bug blowers) be installed to dilute concentration of the gas?

Correct Answer: Option B — shale shaker

The shale shaker is the primary point where drilling mud returns to the surface and releases entrained gases. Installing air movers, or bug blowers, at this location is a critical safety measure to disperse and dilute hazardous gases like H2S before they reach dangerous concentrations on the drill floor.