Problems 6-42 through 6-47 deal with the same two arrays, a and b, which we will assume have been defined in an HDL source file and have the following values: [a] = [10010111], [b] = [00101100]. Output array [z] is also an eight-bit array. Answer Problems 6-42 through 6-47 based on this information. (Assume undefined bits in z are 0.)

Write one or more HDL statements that will take the upper nibble of b and place it in the lower nibble of z. The upper nibble of z should be zero.