@csev A is 2, the unfranked amount
B is 1, the franked amount
C is 6, the credits
D is 4, withholding tax as you say
The others are not needed (I assume 3 is 1+2+6, and 5 is 3-4
A+B+C are added to your taxable income , and you get C and D returned to you as rebates