1) calculate the slack for activities A & D *answer is not A-1 D-5*

I need the correct answer don't use AI tools.

b. Specify the critical path. The critical path is and the project duration is 31 weeks. (Enter your response as a whole number.) c. Calculate the slack for actijities A and D. B. \begin{tabular}{ccc} \hline Activity & Activity Time (weeks) & Immediate Predecessor(s) \\ \hline A & 4 & - \\ B & 3 & - \\ C & 9 & - \\ D & 1 & A, B \\ E & 7 & B \\ F & 2 & D, C \\ G & 9 & E, C \\ H & 12 & F, G \\ \hline \end{tabular}