Ace Test Series

Question

I think the answer is b) and in their solution also they are saying it b) but in option c) is correct. Can anyone confirm? 

Comments

no need to worry

both option same

B) more appropriate

---

Option B says RE but NOT REC strictly.
Option C says RE but may or may not REC.
So option C is correct. 

Answer 1

C is correct

Since Rel's are closed under Kleene closure and concatenation operation, so resultant language is also REL.

B would be incorrect here because it means that the resultant language MUST be Rel but not recursive,

Eg L1 = {}, then L1.(any language)= L1= {}, which is recursive, hence there is case when resultant is recursive.