How do I figure the effect on a crashing solution if task D can start 2 weeks before task C is completed?

I figured out that critical path is A-C-D-E-H-J-K

PROJECT DESCRIPTION AND TIME ESTIMATES (WEEKS) Task Description Most optimistic Most likely Host IP asslmlstlc A Requirements 2 3 4 - E Market assessment 4 7 10 A C Design 5 6 9 A D Development 5 7 16 C E Testing 7 9 10 D F Revising 4 5 6 HE G Documentation 3 6 10 D H Quality assurance 2 4 7 CE I Pricing 2 2 2 B J Production 3 4 14 F.G.H.l K Distribution 2 3 4 J Source: Created by authors. Exhibit 2 PROJECT CRASH DATA Task Normal costs (3} Crash time (weeks) Crash costs (3} A 10.000 3 10,000 E 20.000 5 25.000 C 15.000 5 30,000 D 45.000 5 65,000 E 1 0.000 8 20.000 F 15,000 4 18.000 G 20.000 4 30.000 H 10.000 3 15,000 I 5.000 2 5.000 J 40.000 5 50,000 K 15.000 2 25.000