everything written is correct so far, just need last part

Problem 3.31 Question Help Development of Version 2.0 of a particular accounting software product is being considered by Jose Noguera's technology firm in Baton Rouge. The activities necessary for the completion of this project are listed in the following table: Activity A B C Normal Time (weeks) 4 2 3 8 6 3 4 Crash Time Normal (weeks) Cost 3 $2,200 1 $2,200 3 $600 4 $2,300 3 $900 2 $3,400 2 $1,600 Total Cost with Immediate Crashing Predecessor(s) $2,850 $3,000 $600 $2,600 A $1,200 B $4,800 $2,200 DE a) Based on the given information regarding the activities for the project, the project length = 16 weeks. b) The total cost required for completing this project on normal time = $ 13200 c) For reducing the duration of the project by one week, the activity that should be crashed first is activity D The cost of the project based on the first activity selected for crashing will increase by $ 75. d) The maximum weeks by which the project can be reduced by crashing = 7 weeks. Total cost of crashing the project to minimum (or maximum weeks possible) = $