1. Write a sequence of shift instructions that cause AX to be sign-extended into EAX. In other words, the sign bit of AX is copied into the upper 16 bits of EAX.

2. What happens to the Carry Flag when the SHR AX, 1 instruction is executed?

3. Explain why overflow cannot occur when the MUL and one-operand IMUL instructions execute.

4. Write instructions that multiply -5 by 3 and store the result in a 16-bit variable val1.