Option (a) is correct

Statements A and B are so related that they cannot both be true but can both be false.

Statement A: All physicists are outstanding teachers.

Statement B: No physicists are outstanding teachers.

If statement A is true, it means that every physicist is an outstanding teacher. In this case, statement B must be false because it claims that no physicists are outstanding teachers. However,

if statement A is false, it means that there are physicists who are not outstanding teachers, which allows statement B to be false as well.

Therefore, statements A and B cannot both be true (since they contradict each other), but they can both be false. This makes option (a) the correct answer.

विकल्प (a) सही है।

विरोध के परंपरागत वर्ग (classical square of opposition) के अनुसार, A और E वे कथन हैं जो एक साथ सत्य नहीं हो सकते परन्तु असत्य हो सकतें हैं। इस आधार पर, दिए गए विकल्पों में, "सभी भौतिकशास्त्री उत्कृष्ट शिक्षक होते हैं" [A प्रकार] और "कोई भी भौतिकशास्त्री उत्कृष्ट शिक्षक नहीं होता है" [E प्रकार] ही वे कथन हैं।