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 books are plastic.
Some plastic are cups.
All cups are glass.

Conclusions:
I. Some plastic are books.
II. All plastic are cups.
III. Some cups are glass.