Graduate Pharmacy Aptitude Test (GPAT) 2012 Solved Paper

Given below are four statements in context of Hecogenin:
[P] : It is a saponin
[Q]: It is useful for the semi-synthesis of steroidal drugs
[R] : It is not a glycoalkaloid
[S] : It is obtained from Dioscorea tubers
Choose the correct combination of statements.