PROBLEM: Solids are washing out of the secondary clarifier of the activated sludge plant. Plant personnel increase the return activated sludge (RAS) rate, which slows the problem temporarily, but then it worsens after 30 minutes. What is the CAUSE of the plant problem? O Increasing the RAS caused the DO in the aeration tank to increase O Increasing the RAS decreased the detention time in the clarifier Increasing the RAS increased the detention time in the clarifier O Increasing the RAS increased the detention time in the aeration tank