On disassembling a centrifugal pump for overhaul, the third engineer reports holes drilled axially in the back side of a single suction closed impeller. The reason for the these holes is which of the following?

Correct Answer: Option A — To reduce the axial thrust forces on the impeller

Under USCG National Maritime Center examination standards, the accepted correct answer is: To reduce the axial thrust forces on the impeller.