Answer : C
A . Most powerful and costly order is
LR(0) < SLR(1) < LALR(1) < CLR(1)
B . The grammar generated by LP are CFG but not implying All CFG are LP.
C . Every SLR grammar is unambiguous but not every unambiguous grammar is SLR
D . LR(k) is the most general non back tracking shift reduce parsing method