Which of the following is contradictory to the statement - "No birds are mammals"?

The statement "No birds are mammals" means that there is no overlap between the categories of birds and mammals; they are completely separate groups. 

The option that is contradictory to this statement is: Some birds are mammals.

Important Points

• If some birds are mammals, it means there is an overlap between the categories of birds and mammals. This contradicts the original statement that explicitly stated "No birds are mammals." 

 Some birds are not mammals:
This option is not contradictory to the original statement. It could be true if there are other categories of birds that are not mammals.

All birds are mammals:
This option is also contradictory to the original statement. If all birds are mammals, then there is no distinction between the two categories.

All mammals are birds:
This option is not contradictory to the original statement. It could be true if there are other categories of mammals that are not birds.

In summary, the option that contradicts the statement "No birds are mammals" is "Some birds are mammals."

Additional Information

The square of opposition is a chart that was introduced within classical (categorical) logic to represent the logical relationships holding between certain propositions in virtue of their form.