Referring to the program below, what is the machine code of instruction "LD R1, SIX" in hexadecimal? Program: .ORIG X3000 LD R1, SIX LD R2, NUM AND R3, R3, #0 LOOP ADD R3, R3, R2 ADD R1, R1, #-1 BRP LOOP HALT NUM .FILL #2 FIVE .FILL X0005 SIX .FILL X0006 .END