The least possible Venn diagram for the given statements is as follow :
Conclusions :I. All fishes are swimmers → False (There is no direct relation between fishes and swimmers given. So, it is not definite)
II. No fish is swimmer → False (There is nodirect relation given between fish and swimmer. So, it is not definite)
III. Some fishes are swimmers → False (There is no direct relation given between fish and swimmer. So, it is not definite)
Also, Conclusion (2) and conclusion (3) form
complementary pairs. So, this is an
Either or case.
Hence, the correct answer is
"Either conclusion II or III follows".