Which of these scientists in 1661 defined element in a manner that made it subject to laboratory testing?

(a) Boyle.

(b) Davy.

(c) Berzelius.

(d) Mendeleev.

Earlier in time around 4000 years ago, the concepts related to metals are Greek concepts. But in 1661 an English scientist named as Robert Boyle gave another definition or theory of metal which contradict the earlier Greek theory. Boyles's said that the metal or any element is further divided into various subforms. Boyle's performs various laboratory test to generate this definition.

As the other scientist such as Davy (1778), Berzelius (1779) and Mendeleev (1834) were born very later after the year of definition. Therefore, it made obvious that the definition of the element in the year 1661 is given by Boyle.

Thus option (a) is correct.