Which of the following lies within the scope of responsibility for an expert witness testifying in trial? a. An expert witness must render a view with certainty. b. An expert witness must provide their opinion on whether or not their knowledge and/or research indicates the suspect guilty or not guilty. c. An expert witness must establish to the satisfaction of a trial judge that he or she possesses a particular skill or has knowledge in a trade or profession that will aid the court in determining the truth of the matter at issue. d. An expert witness can advocate one party's cause