Pinnacle Corp. budgeted $$221,620$ of overhead cost for the current year. Actual overhead costs for the year were $$200,640.$ Pinnacle's plantwide allocation base, machine hours, was budgeted at $52,960$ hours. Actual machine hours were $41,140.$ A total of $104,620$ units was budgeted to be produced and $98,000$ units were actually produced. Pinnacle's plantwide factory overhead rate for the current year is:

a$.$ $$4\mathrm{.}18$ per machine hour

b$.$ $$2\mathrm{.}12$ per machine hour

c$.$ $$1\mathrm{.}92$ per machine hour

d$.$ $$3\mathrm{.}79$ per machine hour