Within the concept of the process of scientific evidence, the distinction between "traces" and "physical clues" is based on the fact that:

a) The uncertainty inherent in traces is higher than the uncertainty inherent in clues.
b) Traces pertain to crime scene investigation, and clues pertain to forensic laboratory work.
c) Traces are physical entities that result from activities, and clues are physical entities judged to be connected to the case at hand.
d) All of the above.