Option (b) is correct

According to the traditional square of opposition, the statements that are contrary to each other are those that cannot both be true but can both be false.

In this case, statements A and D are contrary to each other:

A. All plants are oxygen producers.

D. No plants are oxygen producers.

If statement A is true (all plants are oxygen producers), then statement D (no plants are oxygen producers) must be false. Similarly, if statement D is true (no plants are oxygen producers), then statement A (all plants are oxygen producers) must be false.

विकल्प (b) सही है।

पारंपरिक विरोध वर्ग (classical square of opposition) के अनुसार, A और E प्रोपोज़िशन्स परस्पर विपरीत (contrary) होते हैं। अतएव, कथन "सभी पादप ऑक्सीजन उत्पादक होते हैं।" तथा "कोई भी पादप ऑक्सीजन उत्पादक नहीं होता है। " परस्पर विपरीत होंगे।