Which of the following statements are contrary to each other as per traditional square of opposition?

A. All plants are oxygen producers.

B. Some plants are oxygen producers.

C. Some plants are not oxygen producers.

D. No plants are oxygen producers.

Choose the correct answer from the options given below:

 Key PointsIn the traditional square of opposition, there are four types of categorical propositions:

1. Universal affirmative (All S are P)
2. Universal negative (No S are P)
3. Particular affirmative (Some S are P)
4. Particular negative (Some S are not P)

The contrary pairs are those statements that have opposite truth values but have the same subject and predicate terms.

• In this case, statement A "All plants are oxygen producers" is the universal affirmative proposition and statement D "No plants are oxygen producers" is the universal negative proposition.
• These two statements are contrary to each other because if one of them is true, then the other must be false.