Final answer:
The statement that a set of facts is called reasonable ground is generally false; a fact is a true statement verified by evidence, while reasonable ground refers to evidence that provides a basis for belief or action.
Step-by-step explanation:
A set of facts is called reasonable ground is a statement that could be subject to interpretation, depending on the context it is used in. If we consider the definition of a fact, it is a basic statement established by experiment or observation, and all facts are true under the specific conditions of the observation. Hence, a set of facts could provide reasonable ground for conclusions or theories but to define 'reasonable ground' as a set of facts alone may not always hold true.
If we take the context of law or reasoned argument, 'reasonable ground' might refer to enough factually based evidence to believe something is true. Therefore, a more accurate choice from the given options regarding the nature of a fact would be: c. tentative statements about reality or d. statements that are proven to be true.
The answer to the original question, "A set of facts is called reasonable ground," without additional context, is b. False. Facts are true statements that can be verified by compelling evidence; however, 'reasonable ground' more commonly refers to evidence that provides a sound basis for belief, argument or action, rather than the facts themselves.