Let’s first now derive the D flip-flop from RS flip-flop which we have already done:

We first write the truth table for required D flip-flop as

Now we write the excitation table of given FF SR flip-flop as

Now we need to make a arrangement so that we manipulate input D to inputs R, S such that we get the same output with RS FF as that of D FF. So we combine the two tables given above with same outputs in the same row:

Now we design the combinational circuit to convert D input to SR inputs using K-map as:

**K-map for S input:**

**K-map for R input:**

**Hence we convert the SR FF to D FF as:**