After executing 4 PUSH instructions and 6 POP instructions, the value of (SP) is:* Increased by 2 O Decreased by 6 O Decreased by 4 Increased by 4 Decreased by 2 Not changed Increased by 6 The instruction that can be used to exchange between BL and BH is: ROR BX, 8 ROR BX, 16 ROR BH, BL ROL BL, BH RCR BL, BH In order to set the lower nibble of DL, which instruction is used?* OR DL, FOH AND DL, FFH OR DL, 11 H AND DL, 8H AND DL, 80H OOR DL, OFH After executing the following code: * PUSH AX PUSH BX PUSH CX POP AX POP CX POP BX AXNEW=BXOLD, CXNEW=AXOLD, BXNEW=CXOLD AXNEW=BXOLD, CXNEW=CXOLD, BXNEW=AXOLD AXNEW=CXOLD, CXNEW=AXOLD, BXNEW=BXOLD AXNEW=CXOLD, CXNEW=BXOLD, BXNEW=AXOLD AXNEW=AXOLD, CXNEW=CXOLD, BXNEW=BXOLD MOV AL, 50H MOV AH, 70H PUSH AX POP DX TEST DX, 7EH XCHG AL, AH After executing the above code, the value of DX is: 7050H 8000H 7FH 0000H DXold 5070H The instruction (SHR) can be used to perform division for: * both positive and negative numbers both unsigned numbers and positive numbers both signed and unsigned numbers both unsigned numbers and negative numbers unsigned numbers signed numbers