Simple Categorical Conclusion – UGC NET Question

From the statement “All researchers are readers,” we know that every researcher belongs to the larger class of readers. Assuming the class of researchers is non-empty (as in classical categorical logic), this implies that at least one reader is also a researcher, so it is safe to say some readers are researchers. The information about some readers being teachers does not change this basic inclusion.

Option A:
Option A stays within the clear consequence of putting all researchers inside the set of readers: if there are any researchers, then some readers are researchers.

Option B:
Option B would require that some of the readers who are teachers are also researchers, which is not given by the premises and may or may not be true.

Option C:
Option C overstates the relationship by claiming that all researchers are teachers, which is nowhere implied.

Option D:
Option D introduces a particular negative about researchers and teachers without support in the premises, so it goes beyond the logical information available.