Question 14: Mark the letter A, B, C, or D on your answer sheet to indicate the undelined part that needs correction in each of the following questions: Owing (A) to their superior skills, highly competitive (B) athletes have been known (C) to win contests and break records even when suffered (D) from injuries, physical disorders, and infections.
After when + V-ing or when + clause.
So: when suffered => when being suffered
Due to their outstanding skills, potential competitive athletes have been known to win competitions and break records even with injuries, physical disorders and infections.
===============