Context-free languages are closed under:
Union, Kleene closure
Complement, Kleene closure
Cfl are not closed under intersection and complement now choose the correct option, so (B) union and klenne closure.
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check it out http://cs.stackexchange.com/questions/58255/why-dcfl-is-not-closed-under-kleene-star
The context-free languages are closed under union, concatenation and Kleene closure.
so option B
When will be the final official key...