Which of the following sentences contains at least one error?

a$.$ It is a high$-$speed delivery system used for the fast transfer of correspondance, documents, or merchandise.

b$.$ When the codes are compiled, the project manager will provide a listing of project activities that can then be coded.

c$.$ Please check to see if your issue is covered here prior to contacting support, as it will provide you the quickest solution.

d$.$ A review of the yearly budget indicates that departmental funds were inappropriately used.