Answer

Correct Option: (iv) All of the above

Explanation

Chomsky Hierarchy classifies grammars into 4 types:

Type	Name	Production Form	Language Class
Type-0	Unrestricted	$\alpha \rightarrow \beta$, no restriction	Recursively Enumerable (TM)
Type-1	Context-Sensitive	$|\alpha| \le |\beta|$, $\alpha \rightarrow \beta$ with context	CSL (LBA)
Type-2	Context-Free	$A \rightarrow \gamma$, $A\in V$	CFL (PDA)
Type-3	Regular	$A \rightarrow aB \mid a$, $A\rightarrow a$	Regular (FA)

• (i) Regular → Type-3 ✓
• (ii) Context-Free → Type-2 ✓
• (iii) Context-Sensitive → Type-1 ✓

All three are in Chomsky hierarchy (Type-0 is the super-set).

Final Answer

All are types → Option (iv) All of the above.