An oil and gas plant construction project had been progressing on schedule and within budget. Six months into the project, the company owner visits the site for a formal tour. After the tour, the owner asks the project manager to replace the edifice of the office building with marblean expensive cosmetic change! Even though the project manager explained to the owner that this work would escalate the cost of the project and might delay completion, the owner insisted on using the marble. What should the project manager do