Mack's guitar fabrication shop produces low cost, highly durable guitars for beginners. Typically, out of the $100$ guitars that begin production each month, only $80$ percent are considered good enough to sell. The other $20$ percent are scrapped due to quality problems that are identified after they have completed the production process. Each guitar sells for $$250.$

Because some of the production process is automated, each guitar only requires $10$ labor hours. Each employee works an average $160$ hours per month. Labor is paid at $$\frac{10}{?}$ hour, materials cost is $$\frac{40}{?}$ guitar, and overhead is $$8,600.$ After some study, the operations manager recommends three options to in prove the company's multifactor productivity: Improve quality sctthat only $10$ percent are defective.

What is the multifactor productivity of the option? Round to four decimal places. $[$Note: Productivity $=($output$)/($input$).$ Productivity growth $=($current prod. $-$ previous prod.$)/($previous prod.$)]$

$1\mathrm{.}7250$

$0\mathrm{.}9956$

$1\mathrm{.}9417$