The correct answer is (a).
A presumption of fact is a rule of law that requires a court to infer a fact from another fact that is already proven. Presumptions of fact are based on logic, human experience, and natural events and law of nature. For example, the presumption of innocence is based on the idea that people are innocent until proven guilty. The presumption of death after seven years’ absence is based on the idea that people who have been missing for seven years are likely to be dead.
Presumptions of fact can be rebutted by evidence to the contrary. For example, if the prosecution in a criminal case presents evidence that the defendant is guilty, the presumption of innocence is rebutted and the defendant must prove their innocence.
Presumptions of fact are not absolute. They can be overturned by a court if the court finds that they are not reasonable or that they are not supported by the evidence.
(b) is incorrect because presumptions of fact are not based on provisions of law. They are based on logic, human experience, and natural events and law of nature.
(c) is incorrect because presumptions of fact can be rebutted by evidence to the contrary.
(d) is incorrect because presumptions of fact are not always of certain and uniform position. They can be overturned by a court if the court finds that they are not reasonable or that they are not supported by the evidence.