For a given regular language , we can have both regular and non regular (CFG or CSG) grammar..On similar line , for a given CFL , we can have a CFG and a non CFG too..
Hence there is a possibility that a CFG is equivalent to a non CFG in this context.Hence 1st statement is correct..
Now 2nd and 3rd statements we have to consider the fact that if a grammar is left and right linear , then it is not regular..So we can say since S --> ab | abc gives a regular grammar[Also if we follow the basic rule of Type 3 grammar we can arrive at the conclusion which is every production in regular langauge should be V --> T* + T*V [Right linear] or V --> T* + VT* [Left linear] but not both.Hence statement 2 is false..
But in 3rd statement in S --> aA the variable is in right side and in S --> Bb the variable is in left most side of RHS of the production.Hence it is both left and right linear and hence not regular also..It is a linear grammar..
Hence A) is the correct answer
