Q$4.($a$)$ Explain the difference between static memory and dynamic memory. $40\%($b$)$ Implement the following Boolean functions using an $8$ x $4$ ROM: A$($x$,$y$,$z$)=$m$(0,2,4,6)$ B$($x$,$y$,$z$)=$M$(0,1,4)$ C$($x$,$y$,$z$)=$M$(1,5)$ D$($x$,$y$,$z$)=$m$(0,4,6,7)$ If considering the ROM as a memory, specify the memory contents at addresses $2$ and $4.$