The correct answer is “option 4”. EXPLANATION: Option 1: TRUE Language L1 can be written as 0*1*0*. So, L1 is a regular language. Language L2 has one comparison p! = r. So, L2 is a Context-free language. Option 2: TRUE According to the closure property of context-free language, intersection of a regular language with Context-free language is also Context-free language. So, L1 ∩ L2 is context-free. Option 3: TRUE According to the closure property of context-free language (CFL), it is not closed under complementation. So, L2 can be assumed as Context-sensitive language (CSL) since every CFL is CSL. Also, CSL is closed under complementation and every CSL is recursive. So complement of L2 is CSL & hence recursive. Option 4: FALSE According to the closure property of regular language, it is closed under complementation. So, complement is L1 also regular. Hence, the complement of L1 is context-free but not regular is false. The correct answer is “option 4”.