Three statements are given, followed by four conclusions numbered I, II, III and IV. 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:
Some advocates are doctors.
Some doctors are players.
All players are engineers.

Conclusions:
I. Some players are doctors.
II. Some engineers are advocates.
III. All advocates are engineers.
IV. Some engineers are doctors.