Suppose that DS$=1200$H$,$ BX$=0100$H$,$ and SI$=0250$H$.$ Determine the address accessed by each of the following instructions assuming real mode operation:$($a$)$ MOV $[1000$H$],$ DL$($b$)$ MOV $[$SI$+1000$H$],$ AX $($c$)$ MOV DL$,[$BX$+100$H$]$