BackFill Systems allocates manufacturing overhead based on machine hours. Each connector should require $10$ machine hours. According to the static budget, BackFill Systems expected to incur the following: $1,000$ machine hours per month $(100$ connectors $\backslash$times $10$ machine hours per connector $)$

$$8,500$ in variable manufacturing overhead costs

$$9,560$ in fixed manufacturing overhead costs

During August, BackFill Systems actually used $400$ machine hours to make $95$ connectors and spent $$5,500$ in variable manufacturing costs and $$6,000$ in fixed manufacturing overhead costs. BackFill Systems' standard variable manufacturing overhead allocation rate is

A$.$ $$18\mathrm{.}06$ per machine hour.

B$.$ $$9\mathrm{.}56$ per machine hour.

C$.$ $$21\mathrm{.}25$ per machine hour.

D$.$ $$8\mathrm{.}50$ per machine hour.