The x86_64 instruction set architecture uses a variable-length representation with from 1 to 15 bytes. The Instruction Bus is the group of wires that delivers a bit string from instruction memory to the processor. A machine program in instruction memory is a sequence of bytes. How many x86_64 machine instructions can be delivered from instruction memory to the processor at one time using a 32-bit bus? [Hint: there are several cases to consider.]