For which of the following forms of categorical propositions conversion is valid?
(A) Some S is P
(B) Some S is not P
(C) No S is P
(D) All S is P
Choose the correct answer from the options given below:

Correct option is B

Conversion in Categorical Propositions Conversion is a valid logical operation when the subject and predicate terms of a categorical proposition can be interchanged without changing the truth value of the proposition. Let's analyze each option:
1. (A) Some S is P:
· Conversion: Some P is S.
· Valid: This is valid because the proposition remains true when the subject and predicate are interchanged.
2. (C) No S is P:
· Conversion: No P is S.
· Valid: This is valid because the proposition remains true when the subject and predicate are interchanged.
3. (D) All S is P:
· Conversion: Some P is S.
· Valid: This is valid under the partial conversion rule, where "All S is P" can be converted to "Some P is S."
Information Booster: 1. Categorical Propositions:
· A (Universal Affirmative): All S is P
· E (Universal Negative): No S is P
· I (Particular Affirmative): Some S is P
· O (Particular Negative): Some S is not P
2. Conversion Rules:
· Simple Conversion: Applies to E (No S is P) and I (Some S is P).
· Partial Conversion: Applies to A (All S is P), converting it to Some P is S.
· No Valid Conversion: Applies to O (Some S is not P).
3. Conversion Types:
· Simple: Directly interchange subject and predicate (e.g., "No S is P" → "No P is S").
· Partial: Convert a universal affirmative (A) into a particular affirmative (I).
Additional knowledge
(B) Some S is not P:
· Conversion: Some P is not S.
· Invalid: Conversion is not valid for this proposition, as the truth value is not preserved.