Measure<br>John wanted to know how dogs could find electronic devices. He set up a test to measure the chemicals off-gassed by plastic. John used a sensitive device that could detect odors. He found plastic devices gave off a certain chemical as they decayed. John published his research in an esteemed science journal.

Based on that paragraph can we conclude that this sentence is true?
John never experimented on cats

Pick from:
(I). Yes;
(II). It's impossible to say;
(III). No;