Ratterman and Son, is a custom landscaping company. Data in the table below show results for the question "Would you recommend us to a friend?" from $50$ customers who were sampled over the duration of one week.

$\backslash$table$[[\backslash$table$[[$Customer$],[$Number$]],\backslash$table$[[$NPS$],[$Rating$]],\backslash$table$[[$Customer$],[$Number$]],\backslash$table$[[$NPS$],[$Rating$]],\backslash$table$[[$Customer$],[$Number$]],\backslash$table$[[$NPS$],[$Rating$]],\backslash$table$[[$Customer$],[$Number$]],\backslash$table$[[$NPS$],[$Rating$]],\backslash$table$[[$Customer$],[$Number$]],\backslash$table$[[$NPS$],[$Rating$]]],[1,6,11,8,21,4,31,1,41,8],[2,9,12,9,22,9,32,9,42,9],[4,10,13,7,23,9,33,3,43,9],[5,5,15,1,25,9,35,9,45,2],[6,10,16,3,26,10,36,7,46,5],[7,6,17,7,27,5,37,4,47,9],[9,9,18,6,28,10,38,10,48,10],[10,7,20,10,30,6,40,5,50,8]]$

Calculate the net promoter score.

a$.14\%$

b$.17\%$

c$.24\%$

d$.27\%$