This is for an 8085 microprocessor

Write an assembly language instruction that will reset the upper 4-bit group (D7D4) of the accumulator and leave the lower 4-bit group (D3D) of the accumulator unchanged. Write an assembly language instruction that will set the most significant bit D7 of the accumulator and leave the remaining bits (DD) of the accumulator unchanged. Write an assembly language instruction, or routine that will set or reset one of the flag bits if bit D3 in the accumulator is set. It does not matter which flag bit you affect or whether the flag bit is set or reset when D3=1, but you need to explain how your program works in the remarks