Final answer:
A forensic scientist's primary role is to analyze biological samples like blood and tissue, process DNA, and provide scientific evidence to assist law enforcement and courts.
Step-by-step explanation:
The correct answer to the question "Which sentence best describes a forensic scientist's role?" is: A forensic scientist analyzes blood, tissue,and other samples to assist law enforcement. Forensic scientists apply scientific methods to analyze physical evidence related to crimes. They are often involved in analyzing biological samples such as hair, blood, and other body fluids, processing DNA to match with known databases, and providing scientific evidence in courts. Their work may lead to the analysis of other forms of evidence like documents, firearms, and include the use of molecular techniques and databases to assist in crime investigation.