Answer:
Piazza should sue DGA Corporation because he (or she?) was struck by a company vehicle and the driver was acting within the scope of his normal employment tasks. Piazza might also sue Delaney along with DGA, since DGA is a small corporation and as a corporation is considered a separate legal entity whose shareholder equity might be really low.
Piazza can sue for compensatory damages including pain and suffering, medical bills and lost wages.