The artificial system of classification was first used by

Explanation

The artificial system of classification was first introduced by Theophrastus, often called the Father of Botany. He grouped plants on the basis of superficial characters such as form, habit, and utility, dividing them into categories like herbs, shrubs, and trees. This was the earliest attempt to classify living organisms, but it was limited because it did not consider natural relationships. Aristotle, though he classified animals into those with red blood and without red blood, did not propose the first artificial system. Carolus Linnaeus later developed a more natural system along with the binomial nomenclature, which improved upon Theophrastus's work. R.H. Whittaker, much later, proposed the five-kingdom classification in 1969, which was far more advanced and based on natural and evolutionary relationships. Thus, the correct answer is Theophrastus, while the other options represent later or different contributions to classification.