formal languages and automata theory

Which of the following is Context free Grammar

• AB-->C

• X-->AB

• Xa-->AB

• X-->ABC

which of the following is in Greibach normal form

• A-->a

• A-->ab

• A-->aB

• A-->Ca

regular languages are accepted by

• finite automata

• Turing machine

• Pushdown Automata

Pushdown Automata accepts

• recursive language

• context free langauge

• regular language

• context sensitive language

unrestricted grammar is also known as

• Type 0 grammar

• Type 1 Grammar

• Type 2 Grammar

• Type 3 Grammar