(a) Select the best method for project estimating if the final product is not known and the uncertainty is very large. Justify your selected method. (5 marks) (b) Differentiate between top-down and bottom-up estimating approaches. Explain why you would prefer one over the other. (10 marks) (c) Explain how resource scheduling is linked with project priority. (4 marks) (d) Demonstrate how resource scheduling reduces flexibility in managing projects. (6 marks)