3. For a specific CPU design, there are three instruction classes as depicted in Table 1 and run at a clock rate of 100 MHz. For a given program, a compiler can produce the following executed instruction counts as depicted in Table 2. Please calculate the average CPI of this compiler. (A) 4 (B) 2 (C) 1.25 (D) 0.5 (E) All of the above are wrong.