What is the main field of action of forensic science?

I - Forensic science is a branch of medicine that deals with the treatment of patients who have suffered external causes of injury.
II - Forensic science is a scientific method used to study and analyze evidence related to criminal cases.
III - Forensic science is a legal category that deals with public presentations in courtrooms.
IV - Forensic science is a set of knowledge obtained through observation and experimentation, and the formulation and verification of hypotheses.
a) Only I and III are correct.
b) Only II and IV are correct.
c) Only II and III are correct.
d) Only I and IV are correct.
e) Only II, III, and IV are correct.