Concord Inc. currently manufactures a wicket as its main product. The costs per unit are as follows:

$\backslash$table$[[$Direct materials and direct labour,$$11\mathrm{.}70,,,,,,],[$Variable overhead,$2\mathrm{.}80,,,,,,],[$Fixed overhead,$\mathrm{.}10],[$Total$,$$${21\mathrm{.}60}_{?},,,,,,]]$

The fixed overhead is an allocated common cost. How much is the relevant cost of the wicket?

$$18\mathrm{.}80$

$$24\mathrm{.}40$

$$11\mathrm{.}70$

$$14\mathrm{.}50$