The following tasks are associated with an activity$-$based costing system:

$1$ Assignment of cost to products

$2$ Calculation of pool rates

$3$ Identification of cost drivers

$4$ Identification of cost pools

Which of the following choices correctly expresses the proper order of the preceding tasks?

A$.4,3,2,1.$

B$.1,2,3,4.$

C$.3,4,2,1.$

D$.4,2,1,3.$

E$.2,4,1,3.$