12. The Buildtech Education Complex has made an advertisement in the "Ghanaian Times" asking for Contractors to submit tenders for the Development of Sugar Factory at Nkawkaw in Ghana based on the Public Procurement Act, 2003 (Act 663) as amended by the Public Procurement Amendment Act, 2016 (Act 914). Explain to a group of Contractors who have attended the pre-tender conference i. the term "project manager" in a procurement contract and identify roles of project manager under the conditions of contract of public procurement authority of Ghana ii. difference between invitation to treat and Offer iii. Discharge of contract