The correct answer is: A. Reduction to propositional logic, Manipulate rules directly.
Reduction to propositional logic is a technique used in logic to reduce a complex argument to a simpler one that can be more easily analyzed. This is done by translating the argument into propositional logic, which is a formal system of logic that uses propositional variables and logical connectives to represent statements. Once the argument has been translated into propositional logic, it can be analyzed using the rules of propositional logic.
Manipulating rules directly is a technique used in logic to manipulate rules in order to derive new rules. This is done by applying the rules of logic to the existing rules in order to create new rules. This can be a useful technique for generating new rules that can be used in arguments.
The other options are incorrect because they do not accurately describe the two basic types of inferences. Option B is incorrect because it does not mention the technique of reduction to propositional logic. Option C is incorrect because it does not mention the technique of manipulating rules directly. Option D is incorrect because it does not mention either of the two techniques.
In conclusion, the two basic types of inferences are reduction to propositional logic and manipulating rules directly.