Which of the Following Items of Evidence Is Most Valid

Multiple Choice

Which of the following items of evidence is most valid to support a finding that a public utility's repair crews are sometimes required to work under unsafe conditions?

A) Videotapes of repair crews working in a situation that is unsafe.
B) Audio taped testimonials from repair crew members who were required to work under unsafe conditions.
C) Reports showing increases in the number of days of sick leave for individuals on repair crews.
D) Written and signed descriptions from repair crew members of the unsafe conditions that they have had to endure.