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 gorillas are bears.
All pigs are bears.
All bears are tigers.

Conclusions:
I. All pigs are tigers.
II. All tigers are gorillas.
III. Some tigers are pigs.

Only conclusions I and III follow