Given the variables x, y, and z each assigned an integer value, write a fragment of code that assigns the maximum value to a new variable, max_value:
a) max_value = max(x, y, z)
b) max_value = max(x + y, y + z, x + z)
c) max_value = max(x * y, y * z, x * z)
d) max_value = max(x - y, y - z, x - z)
