Which of the following statements represents the function of the compression rings install

Which of the following statements represents the function of the compression rings installed at the top of a diesel Engine piston？

A.Control the amount of lube oil burned in the combustion chamber

B.Transmit heat from the piston to the cylinder liner

C.Prevent damage to ring groove inserts by acting as a heat dam

D.Dissipate combustion chamber gas pressure by channeling it through the ring gap

请帮忙给出正确答案和分析，谢谢！