(a) More registers appear to be a good thing, in terms of reducing the total number of memory accesses a program might require. Given an arithmetic example, Sum=(A+B)-(C+D), support this statement. First, determine the number of memory accesses necessary using MARIE and the two registers for holding memory data values (AC and MBR). Then perform the same arithmetic computation for a processor that has more than three registers to hold memory data values. [8 marks]