complete the following questions out of the section titledQuestions for Review and Discussion. Each question should bethoroughly answered in a minimum of 150 words using support fromthe text and examples when appropriate.a. Why is it preferable to separate need identification anddefining commercial equivalents into two separate stages?b. Why is early supply/supplier important?c. What are the disadvantages of specifying by performance? Whatare the advantages?d. How does a supply professional know that a certain requirementis strategic?