Compiler design

1.Recursive descent parsing is an example of 
a)top-down parsing       b)bottom-up        
c)predictive                   d)none

2.Which of the following is the most powerful parser
a)SLR                 b)LALR
c)Canonical LR   d)operator-precedence

3.Choose the incorrect statement
a)LL(k) grammar has to be CFG.
b)LL(k) grammar has to be unambiguous
c)There are LL(k) grammars that are not context-free
d)LL(k) grammars can't have left recursive non-terminals.

4.The grammar E -->E+E| E*E | a,is
a)ambiguous             c)ambiguous or not depends on the given sentence.
b)unambiguous          d)none

Answers:
1.a
2.c
3.c
4.a