Please help me with a and b with the working and explanation. Thank you!

The activities necessary for the development of a new product are listed in the table below. a. Construct the network diagram, and show the Early Start and Early Finish times and Late Start and Late Finish times for each activity. State the activities on the critical path. (9 marks) b. You are required to shorten the project by 2 weeks. Fully explain how this shortening will be done, and determine the cost implications of this action. (4 marks)