What component of an expert system consists of if/then statements?

A.
Backward chaining

B.
Forward chaining

C.
Inference engine

D.
Knowledge base

Explanation:
Answer D is correct; a knowledge base consists of if/then statements. These statements contain rules that the expert system uses to make decisions.

Incorrect Answers and Explanations: A, B, and C: Answers A, B, and C are incorrect.Forward chaining startswith no premise and works forward to determine a solution. Backward chaining begins with a premise and works backwards. The inference engine follows the tree formed by knowledge base, and fires a rule when there is a match.