Agreed with Ankur Sir but have a point to make here!
Mr.A first has to be appointed as a Director of ABC Pvt. Ltd. and then only he can be appointed as the Managing Director of the same company! Kindly go thorugh the section 2(26) of the Companies Act, 1956 which defines the term and it provides that a Managing Director means a Director..........
Hence, Mr. A should be first appointed as a Director of ABC Pvt. Ltd. and then can be appointed as Managing Director!
This is my opinion and views of other experts are welcome:-0