A 52 year-old woman undergoes a routine low anterior resection for colon cancer and has a temperature of 104° six hours post-op. You look at her wound and it looks purple around the edges and there seems to be some gray drainage. The most appropriate next step in management is-
a. Cefazolin.
b. Ceftriaxone.
c. Zosyn.
d. Reexploration.