June Lives in the Southern Part of Alabama Where Winters

June lives in the southern part of Alabama where winters are normally fairly mild. Last January, during an unusually cold spell, the water pipes in her house froze and burst. She had to look online to find a plumber who was able to come out and repair the pipes the same day. Prior to the frozen pipes, the plumber's services represented a(n) :

A) unsought service.
B) industrial service.
C) specialty service.
D) convenience service.