Presumptions are inferences that a court may or must draw from a particular set of facts. They are generally classified into three categories, as recognized by courts and legal scholarship:
Presumptions of Fact (Permissive Presumptions): These are inferences that the court has the discretion to draw from the facts of the case (e.g., 'may presume'). They are always rebuttable. (Option a)
Rebuttable Presumptions of Law (Compelling Presumptions): These are inferences that the court is bound to draw unless and until the contrary is proved (e.g., 'shall presume'). The burden of proof shifts to the other party to disprove it. (Option b)
Irrebuttable Presumptions of Law (Conclusive Proof): These are inferences that the court must draw, and no evidence is allowed to be given to rebut them (e.g., 'conclusive proof'). (Option c)
Since all three are established classifications of presumptions, the correct answer is "All of them."