Indian Institute of Foreign Trade 2017 Solved Paper

In the following question, two statements are given followed by four conclusions. Taking the given statements to be true, decide which of the given conclusions logically follows from the given statements:
Statements:$$ Some rivers are plateau. No plateau is mountain.
Conclusions:$$ I. Some plateau are rivers.
$$$$ II. Some mountains are rivers.
$$$$ III. Some rivers are not mountains.
$$$$ IV. All mountains are rivers.