Which activity is the best demonstration of j. j. thomsons use of creativity in his work?

The activity which is the best demonstration of Joseph John  Thomson's use of creativity in his work when he devised a better method and equipment in studying cathode rays. This activity led to the discovery of originally termed particles “corpuscles” which are now known as “elections”. This discovery also upended the dominating theory that atoms are the smallest fundamental unit.

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looks like the answer is     c     to me!