The desks in a Primary $$2$$ classroom are arranged in straight rows. Each row has the same number of desks. Robert sits at the desk that is in the third row from the front and the fifth row from the back. He sits at the centre of his row and there are $$4$$ desks to his left. How many desks are in the classroom? 
选项为:A:$$48$$  B:$$54$$  C:$$56$$  D:$$63$$  E:None of the above  请回答其中一个选项.