Context-free languages are closed under −
- Union
- Concatenation
- Kleene Star operation
Therefore Option A is true let check other option also
Context-free languages are not closed under −
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Intersection − If L1 and L2 are context free languages, then L1 ∩ L2 is not necessarily context free.
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Intersection with Regular Language − If L1 is a regular language and L2 is a context free language, then L1 ∩ L2 is a context free language.
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Complement − If L1 is a context free language, then L1’ may not be context free.
B and C are false now let see D
As DPDA accept only DCFL not all CFL therefore D is also false
therefore Option A is correct