Which of the following is true for the given Context Sensitive Language productions?

Im not understanding why should the answer be A?

shivani @shivani1234
29 Aug 2017 12:00 am

for G production rules are: S → bSb | AcA Ab → A, Ab → b, bA → b  s -> bSb  ->bbSbb ->bbAcAbb ->bbAcAb ->bbcAb ->bbcb // we can observe that on left of c we have got more no. of b's So, L(G) = {bncbm | n>=m}  , which is a context free language. For G' , production rules are as follows: S → bSb | AcA Ab → A, Ab → b, bA → b ,  bA → A S -> bSb ->bbSbb ->bbAcAbb ->bbAcAb ->bbAcb ->bbcb  // we observe that on left and right of c , we have got unequal no. of b's  So, we can say that L(G') is a regular language. Ans is (B)

Tarun Kushwaha @tarunkushwah
12 Sep 2017 01:15 am

we can get equal no of b's on either side of c too in G'