For the following four questions: An ISA specifies a word size of 8 bytes, byte addressability, and an address space of 256 K; it uses single-word instructions (i.e. each instruction is a single 8 byte word). What is the size of the MAR? type your answer... 1 point Refer to the ISA description in question 7 What is the size of the MDR? type your answer... 1 point Refer to the ISA description in question 7 What is the size of the IR? type your answer... 1 point Refer to the ISA description in question 7 What is the size of the PC? type your