Three statements are given, followed by three conclusions numbered I, II and III. Assuming the statements to be true, even if they seem to be at variance with commonly known facts, decide which of the conclusions logically follow(s) from the statements.

Statements:

All birds are cows.

Some cows are hens.

Some dogs are birds.

Conclusions:

I. Some dogs are hens.

II. No hens are birds.

III. Some cows are dogs.