Production units

Total Cost $($$$)$

$\backslash$table$[[3700,63675],[4800,82500],[5200,90175]]$

Based on the High, Low Method answer the following, What is the variable cost per unit?

a$.$ $$13\mathrm{.}75$

b$.$ $$17\mathrm{.}67$

c$.$ $$16\mathrm{.}56$

d$.$ $$13\mathrm{.}56$