The following characteristic properties are given in the context of saponins: [P]: Saponins give precipitate by shaking with water. [Q]: Saponins are diterpenes and give foam on shaking with water. [R]: Saponins are triterpenoidal compounds and cause haemolysis of erythrocytes. [S]: They are steroidal or triterpenoidal compounds with tendency to reduce surface tension of water. Choose the correct option.